[llvm] [MathExtras] Favor using the hexadecimal FP constants (PR #123180)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-dylib` running on `linaro-flang-aarch64-dylib` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/50/builds/9425

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
2725.093 [1937/3/4882] Building CXX object tools/mlir/lib/Analysis/CMakeFiles/obj.MLIRAnalysis.dir/DataFlow/IntegerRangeAnalysis.cpp.o
2725.138 [1934/5/4883] Building CXX object tools/mlir/lib/Analysis/CMakeFiles/obj.MLIRAnalysis.dir/DataFlow/DenseAnalysis.cpp.o
2725.822 [1934/4/4884] Building CXX object tools/mlir/lib/Conversion/TosaToArith/CMakeFiles/obj.MLIRTosaToArith.dir/TosaToArithPass.cpp.o
2725.835 [1934/3/4885] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIControlFlow.dir/ControlFlow.cpp.o
2726.112 [1930/6/4886] Linking CXX static library lib/libMLIRAnalysis.a
2726.149 [1930/5/4887] Building CXX object tools/mlir/lib/Conversion/TosaToLinalg/CMakeFiles/obj.MLIRTosaToLinalg.dir/TosaToLinalgPass.cpp.o
2726.797 [1930/4/4888] Building CXX object tools/mlir/lib/Conversion/AMDGPUToROCDL/CMakeFiles/obj.MLIRAMDGPUToROCDL.dir/AMDGPUToROCDL.cpp.o
2727.325 [1930/3/4889] Building CXX object tools/mlir/lib/Conversion/ArithCommon/CMakeFiles/obj.MLIRArithAttrToLLVMConversion.dir/AttrToLLVMConverter.cpp.o
2727.381 [1930/2/4890] Building CXX object tools/mlir/lib/Conversion/AffineToStandard/CMakeFiles/obj.MLIRAffineToStandard.dir/AffineToStandard.cpp.o
2728.058 [1922/9/4891] Building CXX object tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestVisitorsGeneric.cpp.o
FAILED: tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestVisitorsGeneric.cpp.o 
/usr/local/bin/c++ -DGTEST_HAS_RTTI=0 -DMLIR_INCLUDE_TESTS -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/IR -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/../Dialect/Test -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/IR/../Dialect/Test -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 -Wundef -Werror=mismatched-tags -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestVisitorsGeneric.cpp.o -MF tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestVisitorsGeneric.cpp.o.d -o tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestVisitorsGeneric.cpp.o -c /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/TestVisitorsGeneric.cpp
In file included from /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/TestVisitorsGeneric.cpp:9:
/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/../Dialect/Test/TestOps.h:148:10: fatal error: 'TestOps.h.inc' file not found
  148 | #include "TestOps.h.inc"
      |          ^~~~~~~~~~~~~~~
1 error generated.
2728.330 [1922/8/4892] Building CXX object tools/mlir/lib/Conversion/MathToSPIRV/CMakeFiles/obj.MLIRMathToSPIRV.dir/MathToSPIRVPass.cpp.o
2728.338 [1922/7/4893] Building CXX object tools/mlir/lib/Conversion/ArithToEmitC/CMakeFiles/obj.MLIRArithToEmitC.dir/ArithToEmitCPass.cpp.o
2728.709 [1922/6/4894] Building CXX object tools/mlir/lib/Conversion/ArmNeon2dToIntr/CMakeFiles/obj.MLIRArmNeon2dToIntr.dir/ArmNeon2dToIntr.cpp.o
2728.766 [1922/5/4895] Building CXX object tools/mlir/lib/Conversion/ComplexToLLVM/CMakeFiles/obj.MLIRComplexToLLVM.dir/ComplexToLLVM.cpp.o
2728.821 [1922/4/4896] Building CXX object tools/mlir/lib/Conversion/ArithToLLVM/CMakeFiles/obj.MLIRArithToLLVM.dir/ArithToLLVM.cpp.o
2728.875 [1922/3/4897] Building CXX object tools/mlir/lib/Conversion/TosaToTensor/CMakeFiles/obj.MLIRTosaToTensor.dir/TosaToTensor.cpp.o
2728.909 [1922/2/4898] Building CXX object tools/mlir/lib/Conversion/ArithToArmSME/CMakeFiles/obj.MLIRArithToArmSME.dir/ArithToArmSME.cpp.o
2728.938 [1922/1/4899] Building CXX object tools/mlir/lib/Conversion/MathToROCDL/CMakeFiles/obj.MLIRMathToROCDL.dir/MathToROCDL.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/123180