[llvm] [VPlan] Remove VPVectorPointer for part 0 after unrolling. (PR #149735)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `polly-x86_64-linux-plugin` running on `polly-x86_64-gce1` while building `llvm` at step 5 "build".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/158/builds/10238

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

```
Step 5 (build) failure: 'ninja' (failure)
...
[28/121] Generating ../../bin/llvm-dlltool
[29/121] Linking CXX static library lib/libclangBasic.a
[30/121] Linking CXX executable bin/llvm-link
[31/121] Linking CXX executable bin/apinotes-test
[32/121] Linking CXX executable bin/bugpoint
[33/121] Linking CXX executable bin/dsymutil
[34/121] Linking CXX executable bin/clang-offload-packager
[35/121] Linking CXX executable bin/clang-format
[36/121] Linking CXX executable bin/clang-offload-bundler
[37/121] Linking CXX executable bin/llc
FAILED: bin/llc 
: && /usr/bin/c++ -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 -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -fuse-ld=lld -Wl,--color-diagnostics   -Wl,--export-dynamic tools/llc/CMakeFiles/llc.dir/llc.cpp.o tools/llc/CMakeFiles/llc.dir/NewPMDriver.cpp.o -o bin/llc  -Wl,-rpath,"\$ORIGIN/../lib:"  lib/libLLVMX86AsmParser.a  lib/libLLVMX86CodeGen.a  lib/libLLVMNVPTXCodeGen.a  lib/libLLVMX86Desc.a  lib/libLLVMNVPTXDesc.a  lib/libLLVMX86Info.a  lib/libLLVMNVPTXInfo.a  lib/libLLVMAnalysis.a  lib/libLLVMAsmPrinter.a  lib/libLLVMCodeGen.a  lib/libLLVMCodeGenTypes.a  lib/libLLVMCore.a  lib/libLLVMIRPrinter.a  lib/libLLVMIRReader.a  lib/libLLVMMC.a  lib/libLLVMMIRParser.a  lib/libLLVMPasses.a  lib/libLLVMRemarks.a  lib/libLLVMScalarOpts.a  lib/libLLVMSelectionDAG.a  lib/libLLVMSupport.a  lib/libLLVMTarget.a  lib/libLLVMTargetParser.a  lib/libLLVMTransformUtils.a  lib/libLLVMVectorize.a  lib/libLLVMMCDisassembler.a  lib/libLLVMIRPrinter.a  lib/libLLVMCFGuard.a  lib/libLLVMGlobalISel.a  lib/libLLVMSelectionDAG.a  lib/libLLVMCodeGen.a  lib/libLLVMCGData.a  lib/libLLVMCodeGenTypes.a  lib/libLLVMTarget.a  lib/libLLVMObjCARCOpts.a  lib/libLLVMCoroutines.a  lib/libLLVMipo.a  lib/libLLVMVectorize.a  lib/libLLVMSandboxIR.a  lib/libLLVMInstrumentation.a  lib/libLLVMBitWriter.a  lib/libLLVMFrontendOpenMP.a  lib/libLLVMScalarOpts.a  lib/libLLVMAggressiveInstCombine.a  lib/libLLVMFrontendOffloading.a  lib/libLLVMObjectYAML.a  lib/libLLVMFrontendAtomic.a  lib/libLLVMFrontendDirective.a  lib/libLLVMLinker.a  lib/libLLVMHipStdPar.a  lib/libLLVMInstCombine.a  lib/libLLVMTransformUtils.a  lib/libLLVMAnalysis.a  lib/libLLVMProfileData.a  lib/libLLVMSymbolize.a  lib/libLLVMDebugInfoGSYM.a  lib/libLLVMDebugInfoDWARF.a  lib/libLLVMDebugInfoDWARFLowLevel.a  lib/libLLVMDebugInfoPDB.a  lib/libLLVMDebugInfoCodeView.a  lib/libLLVMDebugInfoMSF.a  lib/libLLVMDebugInfoBTF.a  lib/libLLVMObject.a  lib/libLLVMIRReader.a  lib/libLLVMAsmParser.a  lib/libLLVMMCParser.a  lib/libLLVMMC.a  lib/libLLVMBitReader.a  lib/libLLVMTextAPI.a  lib/libLLVMCore.a  lib/libLLVMRemarks.a  lib/libLLVMBitstreamReader.a  lib/libLLVMBinaryFormat.a  lib/libLLVMTargetParser.a  lib/libLLVMSupport.a  lib/libLLVMDemangle.a  -lrt  -ldl  -lm  /usr/lib/x86_64-linux-gnu/libz.so && :
ld.lld: error: undefined symbol: llvm::VPUnrollPartAccessor<1u>::getUnrollPart(llvm::VPUser const&) const
>>> referenced by VPlanTransforms.cpp
>>>               VPlanTransforms.cpp.o:(simplifyRecipe(llvm::VPRecipeBase&, llvm::VPTypeAnalysis&)) in archive lib/libLLVMVectorize.a
>>> did you mean: llvm::VPUnrollPartAccessor<2u>::getUnrollPart(llvm::VPUser const&) const
>>> defined in: lib/libLLVMVectorize.a(VPlanRecipes.cpp.o)
collect2: error: ld returned 1 exit status
[38/121] Linking CXX executable bin/clang-sycl-linker
[39/121] Linking CXX executable bin/diagtool
[40/121] Linking CXX executable bin/clang-scan-deps
[41/121] Linking CXX executable bin/clang-diff
[42/121] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/149735