[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 `llvm-clang-x86_64-expensive-checks-debian` running on `gribozavr4` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/16/builds/17770

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
23.246 [496/8/3618] Building OCaml library llvm_X86
23.267 [495/8/3619] Building AMDGPUGenInstrInfo.inc...
23.278 [495/7/3620] Building OCaml library llvm_executionengine
23.295 [494/7/3621] Building OCaml documentation for llvm_X86
23.303 [493/7/3622] Running utility command for ocaml_llvm_X86
23.391 [493/6/3623] Building OCaml documentation for llvm_executionengine
23.400 [492/6/3624] Running utility command for ocaml_llvm_executionengine
24.685 [492/5/3625] Linking CXX executable bin/lli
25.040 [492/4/3626] Building AMDGPUGenRegisterBank.inc...
26.101 [492/3/3627] Building CXX object lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o
FAILED: lib/Target/RISCV/CMakeFiles/LLVMRISCVCodeGen.dir/RISCVTargetTransformInfo.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DEXPENSIVE_CHECKS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/llvm-clang-x86_64-expensive-checks-debian/build/lib/Target/RISCV -I/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Target/RISCV -I/b/1/llvm-clang-x86_64-expensive-checks-debian/build/include -I/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/include -U_GLIBCXX_DEBUG -fPIC -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 -fvisibility=hidden  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -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/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:710:11: error: no matching function for call to 'costShuffleViaSplitting'
          costShuffleViaSplitting(*this, LT.second, FVTp, Mask, CostKind);
          ^~~~~~~~~~~~~~~~~~~~~~~
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:392:24: note: candidate function not viable: 1st argument ('const llvm::RISCVTTIImpl') would lose const qualifier
static InstructionCost costShuffleViaSplitting(RISCVTTIImpl &TTI, MVT LegalVT,
                       ^
1 error generated.
26.840 [492/2/3628] Building AMDGPUGenRegisterInfo.inc...
34.726 [492/1/3629] Building AMDGPUGenAsmMatcher.inc...
ninja: build stopped: subcommand failed.

```

</details>

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