[clang] [llvm] Revert "[InstCombine] Infer nuw for gep inbounds from base of object" (PR #120460)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-nvptx-nvidia-ubuntu` running on `as-builder-7` while building `clang,llvm` at step 6 "test-build-unified-tree-check-llvm".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/180/builds/10310

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

```
Step 6 (test-build-unified-tree-check-llvm) failure: test (failure)
******************** TEST 'LLVM :: Transforms/PhaseOrdering/X86/excessive-unrolling.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/bin/opt -passes='default<O3>' -unroll-runtime -S /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll | /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/bin/FileCheck /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll
+ /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/bin/opt '-passes=default<O3>' -unroll-runtime -S /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll
+ /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/build/bin/FileCheck /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll
/home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll:182:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds [58 x double], ptr @b, i64 0, i64 [[INDEX]]
              ^
<stdin>:156:67: note: scanning from here
 %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
                                                                  ^
<stdin>:156:67: note: with "INDEX" equal to "%index"
 %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
                                                                  ^
<stdin>:157:2: note: possible intended match here
 %0 = getelementptr inbounds nuw [58 x double], ptr @b, i64 0, i64 %index
 ^

Input file: <stdin>
Check file: /home/buildbot/worker/as-builder-7/ramdisk/llvm-nvptx-nvidia-ubuntu/llvm-project/llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            .
            .
            .
          151: vector.ph: ; preds = %for.body.preheader 
          152:  %n.vec = and i64 %wide.trip.count, 2147483644 
          153:  br label %vector.body 
          154:  
          155: vector.body: ; preds = %vector.body, %vector.ph 
          156:  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ] 
next:182'0                                                                       X error: no match found
next:182'1                                                                         with "INDEX" equal to "%index"
          157:  %0 = getelementptr inbounds nuw [58 x double], ptr @b, i64 0, i64 %index 
next:182'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
next:182'2      ?                                                                         possible intended match
          158:  %1 = getelementptr inbounds nuw i8, ptr %0, i64 16 
next:182'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          159:  %wide.load = load <2 x double>, ptr %0, align 16 
next:182'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          160:  %wide.load4 = load <2 x double>, ptr %1, align 16 
next:182'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          161:  %2 = getelementptr inbounds nuw [58 x double], ptr @c, i64 0, i64 %index 
next:182'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...

```

</details>

https://github.com/llvm/llvm-project/pull/120460