[clang] [Clang] Add `__builtin_reduce_[in_order|assoc]_fadd` for floating-point reductions (PR #176160)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 3118 tests passed
* 7 tests skipped

All executed tests passed, but another part of the build **failed**. Click on a failure below to see the details.

<details>
<summary>tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenItaniumCXXABI.cpp.o</summary>

```
FAILED: tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenItaniumCXXABI.cpp.o
sccache /opt/llvm/bin/clang++ -DCLANG_EXPORTS -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/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/lib/CIR/CodeGen -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/../mlir/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/mlir/include -gmlt -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17 -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -MD -MT tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenItaniumCXXABI.cpp.o -MF tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenItaniumCXXABI.cpp.o.d -o tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenItaniumCXXABI.cpp.o -c /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp
/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp:938:11: error: enumeration value 'OverflowBehavior' not handled in switch [-Werror,-Wswitch]
938 |   switch (ty->getTypeClass()) {
|           ^~~~~~~~~~~~~~~~~~
/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp:1357:11: error: enumeration value 'OverflowBehavior' not handled in switch [-Werror,-Wswitch]
1357 |   switch (ty->getTypeClass()) {
|           ^~~~~~~~~~~~~~~~~~
2 errors generated.
```
</details>
<details>
<summary>tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenFunction.cpp.o</summary>

```
FAILED: tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenFunction.cpp.o
sccache /opt/llvm/bin/clang++ -DCLANG_EXPORTS -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/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/lib/CIR/CodeGen -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/../mlir/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/mlir/include -gmlt -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17 -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -MD -MT tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenFunction.cpp.o -MF tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenFunction.cpp.o.d -o tools/clang/lib/CIR/CodeGen/CMakeFiles/obj.clangCIR.dir/CIRGenFunction.cpp.o -c /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenFunction.cpp:41:13: error: enumeration value 'OverflowBehavior' not handled in switch [-Werror,-Wswitch]
41 |     switch (type->getTypeClass()) {
|             ^~~~~~~~~~~~~~~~~~~~
/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/lib/CIR/CodeGen/CIRGenFunction.cpp:1341:13: error: enumeration value 'OverflowBehavior' not handled in switch [-Werror,-Wswitch]
1341 |     switch (ty->getTypeClass()) {
|             ^~~~~~~~~~~~~~~~~~
2 errors generated.
```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/176160