[llvm] [RISCV][TTI] Use processShuffleMask for shuffle legalization estimate (PR #136191)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-aarch64-ubuntu` running on `linaro-lldb-aarch64-ubuntu` while building `llvm` at step 4 "build".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/16450

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

```
Step 4 (build) failure: build (failure)
...
111.868 [3716/10/2888] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyMCAsmInfo.cpp.o
111.871 [3715/10/2889] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyTargetTransformInfo.cpp.o
111.872 [3714/10/2890] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyMCCodeEmitter.cpp.o
111.884 [3713/10/2891] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyMCTargetDesc.cpp.o
111.885 [3712/10/2892] Building CXX object lib/Target/WebAssembly/TargetInfo/CMakeFiles/LLVMWebAssemblyInfo.dir/WebAssemblyTargetInfo.cpp.o
111.886 [3711/10/2893] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyMCTypeUtilities.cpp.o
111.889 [3710/10/2894] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyWasmObjectWriter.cpp.o
111.891 [3709/10/2895] Building CXX object lib/Target/WebAssembly/MCTargetDesc/CMakeFiles/LLVMWebAssemblyDesc.dir/WebAssemblyTargetStreamer.cpp.o
111.904 [3708/10/2896] Building CXX object lib/Target/WebAssembly/Utils/CMakeFiles/LLVMWebAssemblyUtils.dir/WebAssemblyTypeUtilities.cpp.o
113.467 [3707/10/2897] Building CXX object lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o
FAILED: lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o 
/usr/local/bin/c++ -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/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/Target/RISCV -I/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/llvm/lib/Target/RISCV -I/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/include -I/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/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 -fvisibility=hidden  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o -MF lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o.d -o lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o -c /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
../llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:710:11: error: no matching function for call to 'costShuffleViaSplitting'
  710 |           costShuffleViaSplitting(*this, LT.second, FVTp, Mask, CostKind);
      |           ^~~~~~~~~~~~~~~~~~~~~~~
../llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:392:24: note: candidate function not viable: 1st argument ('const llvm::RISCVTTIImpl') would lose const qualifier
  392 | static InstructionCost costShuffleViaSplitting(RISCVTTIImpl &TTI, MVT LegalVT,
      |                        ^                       ~~~~~~~~~~~~~~~~~
1 error generated.
113.830 [3707/9/2898] Building X86GenRegisterInfo.inc...
113.913 [3707/8/2899] Building X86GenInstrMapping.inc...
113.958 [3707/7/2900] Building X86GenMnemonicTables.inc...
114.202 [3707/6/2901] Building X86GenRegisterBank.inc...
114.408 [3707/5/2902] Building X86GenDAGISel.inc...
114.508 [3707/4/2903] Building X86GenFoldTables.inc...
115.694 [3707/3/2904] Building X86GenGlobalISel.inc...
116.115 [3707/2/2905] Building X86GenFastISel.inc...
119.985 [3707/1/2906] Building X86GenInstrInfo.inc...
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/136191