[clang] [llvm] [OpenACC] Switch Clang to use the Flang 'appertainment' rules for cla… (PR #135372)

[Erich Keane via llvm-commits]

erichkeane wrote:

> `if_present` #135422 merged `finalize` #135415 merged

Picked up in the latest merge, just committed.

https://github.com/llvm/llvm-project/pull/135372