[llvm] [LV] Ignore some costs when loop gets fully unrolled (PR #106699)

[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/10362

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
18.434 [906/26/3076] Building OCaml library llvm_debuginfo
18.600 [905/26/3077] Building OCaml documentation for llvm_debuginfo
18.609 [904/26/3078] Running utility command for ocaml_llvm_debuginfo
19.367 [904/25/3079] Building AMDGPUGenCallingConv.inc...
19.561 [904/24/3080] Building AMDGPUGenMCPseudoLowering.inc...
19.659 [904/23/3081] Building X86GenInstrInfo.inc...
19.724 [904/22/3082] Building RISCVGenGlobalISel.inc...
21.087 [904/21/3083] Building AMDGPUGenRegBankGICombiner.inc...
21.523 [904/20/3084] Building AMDGPUGenPostLegalizeGICombiner.inc...
21.539 [904/19/3085] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o
FAILED: lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.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/Transforms/Vectorize -I/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Transforms/Vectorize -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  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o -MF lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o.d -o lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/LoopVectorize.cpp.o -c /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:2699:49: error: reference to local binding 'IV' declared in enclosing function 'addFullyUnrolledInstructionsToIgnore'
               [&](const User *U) { return U == IV || U == Cmp; }))
                                                ^
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:2694:21: note: 'IV' declared here
  for (const auto &[IV, IndDesc] : IL) {
                    ^
1 error generated.
21.667 [904/18/3086] Building AMDGPUGenPreLegalizeGICombiner.inc...
21.887 [904/17/3087] Building AMDGPUGenSubtargetInfo.inc...
22.166 [904/16/3088] Building AMDGPUGenDisassemblerTables.inc...
22.183 [904/15/3089] Building RISCVGenDAGISel.inc...
22.186 [904/14/3090] Building AMDGPUGenMCCodeEmitter.inc...
22.389 [904/13/3091] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/AsmParser.cpp.o
22.558 [904/12/3092] Building AMDGPUGenSearchableTables.inc...
27.455 [904/11/3093] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
28.295 [904/10/3094] Building RISCVGenSubtargetInfo.inc...
30.030 [904/9/3095] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
30.987 [904/8/3096] Building X86GenAsmMatcher.inc...
31.586 [904/7/3097] Building AMDGPUGenAsmWriter.inc...
32.236 [904/6/3098] Building AMDGPUGenGlobalISel.inc...
32.801 [904/5/3099] Building AMDGPUGenDAGISel.inc...
33.840 [904/4/3100] Building AMDGPUGenInstrInfo.inc...
35.848 [904/3/3101] Building AMDGPUGenRegisterBank.inc...
38.333 [904/2/3102] Building AMDGPUGenRegisterInfo.inc...
45.085 [904/1/3103] Building AMDGPUGenAsmMatcher.inc...
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/106699