[llvm] AMDGPU: Add tonearest and towardzero roundings for intrinsic llvm.fptrunc.round (PR #104486)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clangd-ubuntu-tsan` running on `clangd-ubuntu-clang` while building `llvm` at step 5 "build-clangd-clangd-index-server-clangd-indexer".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/134/builds/3658

Here is the relevant piece of the build log for the reference:
```
Step 5 (build-clangd-clangd-index-server-clangd-indexer) failure: build (failure)
0.009 [4540/18/1] Creating /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/NATIVE...
0.013 [4539/18/2] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o
FAILED: lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o 
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/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/lib/Demangle -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/llvm/lib/Demangle -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/include -I/vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/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 -fno-omit-frame-pointer -gline-tables-only -fsanitize=thread -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o -MF lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o.d -o lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o -c /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/llvm/lib/Demangle/Demangle.cpp
ccache: error: /vol/ccache/ccache.conf: No such file or directory
0.819 [4539/17/3] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/DLangDemangle.cpp.o
1.310 [4539/16/4] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ARMWinEH.cpp.o
1.412 [4539/15/5] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ARMBuildAttrs.cpp.o
1.462 [4539/14/6] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/APSInt.cpp.o
1.486 [4539/13/7] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/RISCVISAUtils.cpp.o
1.542 [4539/12/8] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/RustDemangle.cpp.o
1.713 [4539/11/9] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/MicrosoftDemangleNodes.cpp.o
1.811 [4539/10/10] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ScaledNumber.cpp.o
1.891 [4539/9/11] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/RISCVAttributeParser.cpp.o
2.442 [4539/8/12] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/APFixedPoint.cpp.o
2.482 [4539/7/13] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/MicrosoftDemangle.cpp.o
2.824 [4539/6/14] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ARMAttributeParser.cpp.o
2.870 [4539/5/15] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ScopedPrinter.cpp.o
4.197 [4539/4/16] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/APInt.cpp.o
4.530 [4539/3/17] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/APFloat.cpp.o
5.567 [4539/2/18] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/ItaniumDemangle.cpp.o
16.028 [4539/1/19] Configuring NATIVE LLVM...
-- The C compiler identification is Clang 18.1.0
-- The CXX compiler identification is Clang 18.1.0
-- The ASM compiler identification is Clang with GNU-like command-line
-- Found assembler: /usr/bin/clang
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/clang - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- bolt project is disabled
-- clang project is enabled
-- clang-tools-extra project is enabled
-- compiler-rt project is disabled
-- cross-project-tests project is disabled
-- libc project is disabled
-- libclc project is disabled
-- lld project is disabled
-- lldb project is disabled
-- mlir project is disabled
-- openmp project is disabled
-- polly project is disabled
-- pstl project is disabled
-- flang project is disabled

```

https://github.com/llvm/llvm-project/pull/104486