[llvm] [Attributor] Use known non-flat AS before `getAssumedAddrSpace` (PR #143221)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-cmake-x86_64-avx512-linux` running on `avx512-intel64` while building `llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/133/builds/17501

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

```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'LLVM :: Transforms/OpenMP/remove_globalization.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/opt -S -passes=openmp-opt < /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/Transforms/OpenMP/remove_globalization.ll | /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/FileCheck /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/Transforms/OpenMP/remove_globalization.ll # RUN: at line 2
+ /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/opt -S -passes=openmp-opt
+ /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/FileCheck /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/Transforms/OpenMP/remove_globalization.ll
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/opt: WARNING: failed to create target machine for 'nvptx64': unable to get target for 'nvptx64', see --version and --triple.
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/Transforms/OpenMP/remove_globalization.ll:166:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: [[UB_PTR:%.*]] = alloca i32, align 4
              ^
<stdin>:61:31: note: scanning from here
 %iv_ptr = alloca i32, align 4
                              ^
<stdin>:74:2: note: possible intended match here
 %inc = add i32 %iv, 1
 ^

Input file: <stdin>
Check file: /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/Transforms/OpenMP/remove_globalization.ll

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

Input was:
<<<<<<
            .
            .
            .
           56:  
           57: ; Function Attrs: nosync nounwind 
           58: define internal void @convert_and_move_alloca() #1 { 
           59: entry: 
           60:  %.h2s = alloca i8, i64 4, align 4 
           61:  %iv_ptr = alloca i32, align 4 
next:166'0                                   X error: no match found
           62:  br label %initloop 
next:166'0     ~~~~~~~~~~~~~~~~~~~~
           63:  
next:166'0     ~
           64: initloop: ; preds = %entry 
next:166'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~
           65:  store i32 0, ptr %iv_ptr, align 4 
next:166'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           66:  br label %loopbody 
next:166'0     ~~~~~~~~~~~~~~~~~~~~
            .
            .
            .
           69:  %iv = load i32, ptr %iv_ptr, align 4 
...

```

</details>

https://github.com/llvm/llvm-project/pull/143221