[llvm-branch-commits] [libcxx] release/18.x: [libcxx] [modules] Add _LIBCPP_USING_IF_EXISTS on aligned_alloc (#89827) (PR #89894)

[Tom Stellard via llvm-branch-commits]

tstellar wrote:

@mstorsjo (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix.  When you are done, please add the release:note label to this PR.

https://github.com/llvm/llvm-project/pull/89894