[clang] [Clang] Fix coroutine promise with inherited allocation functions (PR #179141)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 52358 tests passed
* 926 tests skipped
* 1 test failed

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

### Clang
<details>
<summary>Clang.SemaCXX/coroutine-inherited-allocator.cpp</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
c:\_work\llvm-project\llvm-project\build\bin\clang.exe -cc1 -internal-isystem C:\_work\llvm-project\llvm-project\build\lib\clang\23\include -nostdsysteminc -triple x86_64-linux-gnu C:\_work\llvm-project\llvm-project\clang\test\SemaCXX\coroutine-inherited-allocator.cpp -std=c++20 -fsyntax-only -verify
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\clang.exe' -cc1 -internal-isystem 'C:\_work\llvm-project\llvm-project\build\lib\clang\23\include' -nostdsysteminc -triple x86_64-linux-gnu 'C:\_work\llvm-project\llvm-project\clang\test\SemaCXX\coroutine-inherited-allocator.cpp' -std=c++20 -fsyntax-only -verify
# .---command stderr------------
# | error: no expected directives found: consider use of 'expected-no-diagnostics'
# | 1 error generated.
# `-----------------------------
# error: command failed with exit status: 1

--

```
</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/179141