cfi: Suppress CFI diagnostic in std::__allocate_unique_temporary_buffer

See https://issues.chromium.org/issues/367439556#comment17

Bug: 367439556
Change-Id: I8798abd98bacba13ab4d580b950948e7e2e8b43c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5882894
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1358822}
NOKEYCHECK=True
GitOrigin-RevId: c56bf6112afb6443d0cefef012f2448d8d24b7bf