[llvm] [CAS] Add OnDiskTrieRawHashMap (PR #114100)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-armv8-quick` running on `linaro-clang-armv8-quick` while building `llvm` at step 4 "build stage 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/154/builds/22097

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

```
Step 4 (build stage 1) failure: 'ninja' (failure)
...
[386/4920] Linking CXX static library lib/libLLVMTableGenCommon.a
[387/4920] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeRecordHelpers.cpp.o
[388/4920] Building CXX object lib/DebugInfo/CodeView/CMakeFiles/LLVMDebugInfoCodeView.dir/TypeTableCollection.cpp.o
[389/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/MachOObjectFormat.cpp.o
[390/4920] Building CXX object lib/DebugInfo/BTF/CMakeFiles/LLVMDebugInfoBTF.dir/BTFParser.cpp.o
[391/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/OrcRTBridge.cpp.o
[392/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/OrcError.cpp.o
[393/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/AllocationActions.cpp.o
[394/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/ObjectFormats.cpp.o
[395/4920] Building CXX object lib/CAS/CMakeFiles/LLVMCAS.dir/OnDiskTrieRawHashMap.cpp.o
FAILED: lib/CAS/CMakeFiles/LLVMCAS.dir/OnDiskTrieRawHashMap.cpp.o 
/usr/local/bin/c++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/clang-armv8-quick/stage1/lib/CAS -I/home/tcwg-buildbot/worker/clang-armv8-quick/llvm/llvm/lib/CAS -I/home/tcwg-buildbot/worker/clang-armv8-quick/stage1/include -I/home/tcwg-buildbot/worker/clang-armv8-quick/llvm/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/CAS/CMakeFiles/LLVMCAS.dir/OnDiskTrieRawHashMap.cpp.o -MF lib/CAS/CMakeFiles/LLVMCAS.dir/OnDiskTrieRawHashMap.cpp.o.d -o lib/CAS/CMakeFiles/LLVMCAS.dir/OnDiskTrieRawHashMap.cpp.o -c /home/tcwg-buildbot/worker/clang-armv8-quick/llvm/llvm/lib/CAS/OnDiskTrieRawHashMap.cpp
../llvm/llvm/lib/CAS/OnDiskTrieRawHashMap.cpp:287:54: error: non-constant-expression cannot be narrowed from type 'uint64_t' (aka 'unsigned long long') to 'size_t' (aka 'unsigned int') in initializer list [-Wc++11-narrowing]
  287 |     return TrieHashIndexGenerator{Root.getNumBits(), getNumSubtrieBits(), Hash};
      |                                                      ^~~~~~~~~~~~~~~~~~~
../llvm/llvm/lib/CAS/OnDiskTrieRawHashMap.cpp:287:54: note: insert an explicit cast to silence this issue
  287 |     return TrieHashIndexGenerator{Root.getNumBits(), getNumSubtrieBits(), Hash};
      |                                                      ^~~~~~~~~~~~~~~~~~~
      |                                                      static_cast<size_t>( )
1 error generated.
[396/4920] Linking CXX static library lib/libLLVMCodeGenTypes.a
[397/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/SimpleRemoteEPCUtils.cpp.o
[398/4920] Building CXX object lib/DebugInfo/BTF/CMakeFiles/LLVMDebugInfoBTF.dir/BTFContext.cpp.o
[399/4920] Building CXX object lib/ExecutionEngine/Orc/Shared/CMakeFiles/LLVMOrcShared.dir/SymbolStringPool.cpp.o
[400/4920] Building RISCVTargetParserDef.inc...
[401/4920] Linking CXX static library lib/libLLVMRemarks.a
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/114100