[clang] [llvm] [mlir] IR: Promote "denormal-fp-math" to a first class attribute (PR #174293)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `clang,llvm,mlir` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/31174

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
0.020 [5387/8/1] Generating VCSRevision.h
0.727 [5387/7/2] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/FloatingPointMode.cpp.o
FAILED: lib/Support/CMakeFiles/LLVMSupport.dir/FloatingPointMode.cpp.o 
/opt/ccache/bin/g++ -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/../third-party/siphash/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-array-bounds -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -std=c++17 -MD -MT lib/Support/CMakeFiles/LLVMSupport.dir/FloatingPointMode.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/FloatingPointMode.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/FloatingPointMode.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/FloatingPointMode.cpp
In file included from /usr/include/c++/9/cassert:44,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/raw_ostream.h:20,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:21,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/FloatingPointMode.cpp:9:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h: In member function ‘constexpr uint32_t llvm::DenormalFPEnv::toIntValue() const’:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:304:31: error: call to non-‘constexpr’ function ‘bool llvm::DenormalMode::isValid() const’
  304 |     assert(DefaultMode.isValid() && F32Mode.isValid());
      |            ~~~~~~~~~~~~~~~~~~~^~
In file included from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/FloatingPointMode.cpp:9:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h: In member function ‘constexpr bool llvm::DenormalFPEnv::operator==(llvm::DenormalFPEnv) const’:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:318:24: error: call to non-‘constexpr’ function ‘bool llvm::DenormalMode::operator==(llvm::DenormalMode) const’
  318 |     return DefaultMode == Other.DefaultMode && F32Mode == Other.F32Mode;
      |            ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
0.746 [5387/6/3] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/KnownFPClass.cpp.o
FAILED: lib/Support/CMakeFiles/LLVMSupport.dir/KnownFPClass.cpp.o 
/opt/ccache/bin/g++ -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/../third-party/siphash/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-array-bounds -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -std=c++17 -MD -MT lib/Support/CMakeFiles/LLVMSupport.dir/KnownFPClass.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/KnownFPClass.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/KnownFPClass.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/KnownFPClass.cpp
In file included from /usr/include/c++/9/cassert:44,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/raw_ostream.h:20,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:21,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/KnownFPClass.h:17,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/KnownFPClass.cpp:14:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h: In member function ‘constexpr uint32_t llvm::DenormalFPEnv::toIntValue() const’:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:304:31: error: call to non-‘constexpr’ function ‘bool llvm::DenormalMode::isValid() const’
  304 |     assert(DefaultMode.isValid() && F32Mode.isValid());
      |            ~~~~~~~~~~~~~~~~~~~^~
In file included from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/KnownFPClass.h:17,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/KnownFPClass.cpp:14:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h: In member function ‘constexpr bool llvm::DenormalFPEnv::operator==(llvm::DenormalFPEnv) const’:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:318:24: error: call to non-‘constexpr’ function ‘bool llvm::DenormalMode::operator==(llvm::DenormalMode) const’
  318 |     return DefaultMode == Other.DefaultMode && F32Mode == Other.F32Mode;
      |            ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
0.746 [5387/5/4] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/Z3Solver.cpp.o
FAILED: lib/Support/CMakeFiles/LLVMSupport.dir/Z3Solver.cpp.o 
/opt/ccache/bin/g++ -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/../third-party/siphash/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-array-bounds -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -std=c++17 -MD -MT lib/Support/CMakeFiles/LLVMSupport.dir/Z3Solver.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/Z3Solver.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/Z3Solver.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/Z3Solver.cpp
In file included from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Support/Z3Solver.cpp:9:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/ScopeExit.h:29:26: warning: ‘nodiscard’ attribute applied to ‘llvm::scope_exit<Callable>::scope_exit(Fp&&)’ with void return type [-Wattributes]
   29 |   [[nodiscard]] explicit scope_exit(Fp &&F)
      |                          ^~~~~~~~~~
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/ScopeExit.h:32:17: warning: ‘nodiscard’ attribute applied to ‘llvm::scope_exit<Callable>::scope_exit(llvm::scope_exit<Callable>&&)’ with void return type [-Wattributes]
   32 |   [[nodiscard]] scope_exit(scope_exit &&Rhs)
      |                 ^~~~~~~~~~
In file included from /usr/include/c++/9/cassert:44,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/raw_ostream.h:20,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:21,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/ADT/APFloat.h:20,
                 from /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include/llvm/Support/SMTAPI.h:17,

```

</details>

https://github.com/llvm/llvm-project/pull/174293