[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 `ml-opt-dev-x86-64` running on `ml-opt-dev-x86-64-b2` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/137/builds/17333

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
62.542 [388/10/3429] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86ISelLowering.cpp.o
62.544 [388/9/3430] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86IndirectThunks.cpp.o
62.617 [388/8/3431] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86SpeculativeLoadHardening.cpp.o
62.645 [388/7/3432] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86TargetTransformInfo.cpp.o
62.687 [388/6/3433] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86InstrInfo.cpp.o
62.840 [388/5/3434] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86ISelDAGToDAG.cpp.o
62.940 [387/5/3435] Linking CXX static library lib/libLLVMX86CodeGen.a
64.199 [387/4/3436] Building AMDGPUGenRegisterBank.inc...
66.209 [387/3/3437] Building AMDGPUGenRegisterInfo.inc...
68.183 [386/3/3438] Building CXX object lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o
FAILED: lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o 
ccache /usr/bin/c++ -DCPUINFO_SUPPORTED_PLATFORM=1 -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/b/ml-opt-dev-x86-64-b1/build/lib/Target/RISCV -I/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV -I/b/ml-opt-dev-x86-64-b1/build/include -I/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include -isystem /tmp/tflitebuild/tensorflow/include -isystem /tmp/tflitebuild/eigen/include/eigen3 -isystem /tmp/tflitebuild/abseil-cpp/include -isystem /tmp/tflitebuild/flatbuffers/include -isystem /tmp/tflitebuild/gemmlowp/include/gemmlowp -isystem /tmp/tflitebuild/ml_dtypes/src/ml_dtypes -isystem /tmp/tflitebuild/ml_dtypes/src/ml_dtypes/ml_dtypes -isystem /tmp/tflitebuild/ruy/include -isystem /tmp/tflitebuild/cpuinfo/include -isystem /tmp/tflitebuild/ARM_NEON_2_x86_SSE/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -fvisibility=hidden  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -DEIGEN_NEON_GEBP_NR=4 -DTFL_STATIC_LIBRARY_BUILD -std=c++17 -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 /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp: In member function ‘llvm::InstructionCost llvm::RISCVTTIImpl::getShuffleCost(llvm::TargetTransformInfo::ShuffleKind, llvm::VectorType*, llvm::ArrayRef<int>, llvm::TargetTransformInfo::TargetCostKind, int, llvm::VectorType*, llvm::ArrayRef<const llvm::Value*>, const llvm::Instruction*) const’:
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:710: error: binding reference of type ‘llvm::RISCVTTIImpl&’ to ‘const llvm::RISCVTTIImpl’ discards qualifiers
  710 |           costShuffleViaSplitting(*this, LT.second, FVTp, Mask, CostKind);
      | 
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:392: note:   initializing argument 1 of ‘llvm::InstructionCost costShuffleViaSplitting(llvm::RISCVTTIImpl&, llvm::MVT, llvm::VectorType*, llvm::ArrayRef<int>, llvm::TargetTransformInfo::TargetCostKind)’
  392 | static InstructionCost costShuffleViaSplitting(RISCVTTIImpl &TTI, MVT LegalVT,
      | 
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp: At global scope:
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:392: warning: ‘llvm::InstructionCost costShuffleViaSplitting(llvm::RISCVTTIImpl&, llvm::MVT, llvm::VectorType*, llvm::ArrayRef<int>, llvm::TargetTransformInfo::TargetCostKind)’ defined but not used [-Wunused-function]
82.857 [386/2/3439] Building InstCombineTables.inc...
104.862 [386/1/3440] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

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