[llvm] [SLP]Improve minbitwidth analysis. (PR #78976)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> > Seems to break the build, maybe on GCC only?
> > ```
> > 
> > /var/llvm-compile-time-tracker/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3617:24: error: declaration of ‘llvm::TargetTransformInfo* llvm::slpvectorizer::BoUpSLP::TTI’ changes meaning of ‘TTI’ [-fpermissive]
> >  3617 |   TargetTransformInfo *TTI;
> >       |                        ^~~
> > In file included from /var/llvm-compile-time-tracker/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:48:
> > /var/llvm-compile-time-tracker/llvm-project/llvm/include/llvm/Analysis/TargetTransformInfo.h:206:29: note: ‘TTI’ declared here as ‘typedef class llvm::TargetTransformInfo llvm::TTI’
> >   206 | typedef TargetTransformInfo TTI;
> >       |                             ^~~
> > ```
> 
> Am, I did not touch this code. Probably, some kind of side effect. Could you provide full error report?

https://github.com/dtcxzyw/llvm-ci/actions/runs/8160865465/job/22308394053
```
[624/1925] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o
FAILED: lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o 
/usr/bin/c++ -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-build/lib/Transforms/Vectorize -I/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/lib/Transforms/Vectorize -I/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-build/include -I/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -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 -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -MD -MT lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o -MF lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o.d -o lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/SLPVectorizer.cpp.o -c /home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:3617:24: error: declaration of ‘llvm::TargetTransformInfo* llvm::slpvectorizer::BoUpSLP::TTI’ changes meaning of ‘TTI’ [-fpermissive]
 3617 |   TargetTransformInfo *TTI;
      |                        ^~~
In file included from /home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:48:
/home/dtcxzyw/llvm-ci/rv64gc-O3-thinlto/llvm-project/llvm/include/llvm/Analysis/TargetTransformInfo.h:206:29: note: ‘TTI’ declared here as ‘typedef class llvm::TargetTransformInfo llvm::TTI’
  206 | typedef TargetTransformInfo TTI;
      |                             ^~~
[625/1925] Building CXX object lib/Transforms/ObjCARC/CMakeFiles/LLVMObjCARCOpts.dir/ObjCARCContract.cpp.o
```

Related commits:
```
from 1e828f838cc0f15074f3dbbb04929c06ef0c9729 to 041638c4294a9a8375851e0add1ab2c99412c032

041638c4294a9a8375851e0add1ab2c99412c032 [libc][stdbit] implement stdc_bit_width (C23) (#83892)
233f750c3dad14e330f5358e8dbcc6c30e805edb [flang] Catch more bad pointer initialization targets (#83731)
9f67f19614e952ede385a59bb62f7b57771ca4c3 [gn] Remove ScudoBenchmarks
2807ea6b8047780b5e66a122faf09fae786c917b [HLSL] implement the any intrinsic (#83903)
b2ca23aed802abc43ed216ce9bf4c80c056a04c0 [HLSL] implement exp intrinsic (#83832)
06fea93341ae7d0d0faa82c4c8704591963c2d8c [TextAPI] add missing platforms for translating triples to tapi targets
643b31dbe8a515e007a0f1b2e1072c34e461b778 [HLSL] implement `mad` intrinsic (#83826)
a730ed7c1a4a35f5219df720ffb0ba6122d64fe4 [SLP]Improve minbitwidth analysis.
1b1aea79194117d8f1729ef9c8f80454aea381fe AMDGPU: Make s_wait_samplecnt(_bvhcnt) dependent on hasImageInsts, NFC (#83932)
f836048a2b452f5f2a8440c9f5945ee1a7bcdac2 [gn] port 6fd27d5b0321f (no more module.modulemap.in)
f33f66be7dc586a597437d7ce7619d87e8637209 [NFC][RemoveDIs] Always use iterators for inserting PHIs
```

https://github.com/llvm/llvm-project/pull/78976