[clang] [llvm] [AMDGPU] Support loop unrolled asyncmark (PR #212929)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 179848 tests passed
* 3601 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.CodeGen/AMDGPU/asyncmark-non-constant-err.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
not /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -global-isel=0 -mtriple=amdgpu12.50 -filetype=null /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/asyncmark-non-constant-err.ll 2>&1 | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/asyncmark-non-constant-err.ll
# executed command: not /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -global-isel=0 -mtriple=amdgpu12.50 -filetype=null /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/asyncmark-non-constant-err.ll
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/asyncmark-non-constant-err.ll
# note: command had no output on stdout or stderr

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/212929