[llvm] [CodeGen] Use temp symbol for MBBs (PR #95031)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/564

Here is the relevant piece of the build log for the reference:
```
Step 5 (build-unified-tree) failure: build (failure)
...
16.898 [516/164/5772] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineModuleInfoImpls.cpp.o
16.943 [516/163/5773] Building CXX object lib/MC/CMakeFiles/LLVMMC.dir/MCObjectFileInfo.cpp.o
17.049 [516/162/5774] Building CXX object lib/MC/CMakeFiles/LLVMMC.dir/MCAsmInfo.cpp.o
17.070 [516/161/5775] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineFunctionAnalysis.cpp.o
17.149 [516/160/5776] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/COFFMasmParser.cpp.o
17.180 [516/159/5777] Building CXX object lib/MC/MCDisassembler/CMakeFiles/LLVMMCDisassembler.dir/Disassembler.cpp.o
17.395 [516/158/5778] Building CXX object lib/MC/CMakeFiles/LLVMMC.dir/MCELFStreamer.cpp.o
17.483 [516/157/5779] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/ELFAsmParser.cpp.o
17.627 [516/156/5780] Building CXX object lib/Target/PowerPC/MCTargetDesc/CMakeFiles/LLVMPowerPCDesc.dir/PPCMCExpr.cpp.o
17.674 [516/155/5781] Building CXX object lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o
FAILED: lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o 
ccache /home/buildbots/llvm-external-buildbots/clang.16.0.1/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/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/lib/MC -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/lib/MC -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include -fPIC -fno-semantic-interposition -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 -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o -MF lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o.d -o lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o -c /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/lib/MC/MCContext.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/lib/MC/MCContext.cpp:328:61: error: invalid operands to binary expression ('StringRef' and 'const Twine')
  return createRenamableSymbol(MAI->getPrivateLabelPrefix() << Name,
                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~~~
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/ADT/Twine.h:572:23: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
  inline raw_ostream &operator<<(raw_ostream &OS, const Twine &RHS) {
                      ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/Support/raw_ostream.h:783:14: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
raw_ostream &operator<<(raw_ostream &OS, std::nullopt_t);
             ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/Support/VersionTuple.h:191:14: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
raw_ostream &operator<<(raw_ostream &Out, const VersionTuple &V);
             ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/ADT/APInt.h:2128:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream &operator<<(raw_ostream &OS, const APInt &I) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/MC/MCInst.h:241:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream& operator<<(raw_ostream &OS, const MCOperand &MO) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/MC/MCInst.h:246:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream& operator<<(raw_ostream &OS, const MCInst &MI) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/MC/MCExpr.h:138:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/MC/MCLabel.h:49:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream &operator<<(raw_ostream &OS, const MCLabel &Label) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/MC/MCSymbol.h:437:21: note: candidate function not viable: no known conversion from 'StringRef' to 'raw_ostream &' for 1st argument
inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) {
                    ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/Support/raw_ostream.h:437:1: note: candidate template ignored: requirement 'std::is_base_of_v<llvm::raw_ostream, llvm::StringRef>' was not satisfied [with OStream = StringRef, T = Twine]
operator<<(OStream &&OS, const T &Value) {
^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/llvm/include/llvm/Support/raw_ostream.h:787:14: note: candidate template ignored: could not match 'const std::optional<T>' against 'const Twine'
raw_ostream &operator<<(raw_ostream &OS, const std::optional<T> &O) {
             ^
1 error generated.

```

https://github.com/llvm/llvm-project/pull/95031