[llvm] [CodeGen] Introduce `MachineDomTreeUpdater` (PR #95369)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-x86_64-debian-fast` running on `gribozavr4` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/56/builds/1001

Here is the relevant piece of the build log for the reference:
```
Step 5 (build-unified-tree) failure: build (failure)
...
                  ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:2189:9: warning: HTML tag 'a' requires an end tag [-Wdocumentation-html]
  /// "<a, a+n, a+2n, a+3n, ...>" where a is integer and n is a non-zero integer,
        ^
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/IfConversion.cpp:35:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/TargetLowering.h:5278:14: warning: parameter 'N' not found in the function declaration [-Wdocumentation]
  /// \param N Node to expand
             ^
5 warnings generated.
17.432 [4238/96/1586] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDomTreeUpdater.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDomTreeUpdater.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/clang-x86_64-debian-fast/llvm.obj/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include -std=c++11 -Wdocumentation -Wno-documentation-deprecated-sync -fPIC -fvisibility-inlines-hidden -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 -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDomTreeUpdater.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDomTreeUpdater.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDomTreeUpdater.cpp.o -c /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachineDomTreeUpdater.cpp
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachineDomTreeUpdater.cpp:14:
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachineDomTreeUpdater.h:21:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:53:3: error: constructor cannot be redeclared
  MachinePostDominatorTree(MachineFunction &MF) { recalculate(MF); }
  ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:51:12: note: previous definition is here
  explicit MachinePostDominatorTree(MachineFunction &MF) { recalculate(MF); }
           ^
1 error generated.
17.748 [4238/95/1587] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/LiveIntervals.cpp.o
17.806 [4238/94/1588] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineCFGPrinter.cpp.o
17.881 [4238/93/1589] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/BranchFolding.cpp.o
18.123 [4238/92/1590] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/LiveVariables.cpp.o
18.124 [4238/91/1591] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockFrequencyInfo.cpp.o
18.131 [4238/90/1592] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineFrameInfo.cpp.o
18.162 [4238/89/1593] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachinePostDominators.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachinePostDominators.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/clang-x86_64-debian-fast/llvm.obj/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include -std=c++11 -Wdocumentation -Wno-documentation-deprecated-sync -fPIC -fvisibility-inlines-hidden -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 -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachinePostDominators.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachinePostDominators.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachinePostDominators.cpp.o -c /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachinePostDominators.cpp
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachinePostDominators.cpp:14:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:53:3: error: constructor cannot be redeclared
  MachinePostDominatorTree(MachineFunction &MF) { recalculate(MF); }
  ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:51:12: note: previous definition is here
  explicit MachinePostDominatorTree(MachineFunction &MF) { recalculate(MF); }
           ^
1 error generated.
18.203 [4238/88/1594] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineCycleAnalysis.cpp.o
18.391 [4238/87/1595] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineDominanceFrontier.cpp.o
18.446 [4238/86/1596] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineCombiner.cpp.o
18.600 [4238/85/1597] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockPlacement.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockPlacement.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/clang-x86_64-debian-fast/llvm.obj/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen -I/b/1/clang-x86_64-debian-fast/llvm.obj/include -I/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include -std=c++11 -Wdocumentation -Wno-documentation-deprecated-sync -fPIC -fvisibility-inlines-hidden -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 -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockPlacement.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockPlacement.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBlockPlacement.cpp.o -c /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachineBlockPlacement.cpp
In file included from /b/1/clang-x86_64-debian-fast/llvm.src/llvm/lib/CodeGen/MachineBlockPlacement.cpp:44:
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:53:3: error: constructor cannot be redeclared
  MachinePostDominatorTree(MachineFunction &MF) { recalculate(MF); }
  ^
/b/1/clang-x86_64-debian-fast/llvm.src/llvm/include/llvm/CodeGen/MachinePostDominators.h:51:12: note: previous definition is here

```

https://github.com/llvm/llvm-project/pull/95369