[clang] [driver][AIX] Accept '32_64' and 'any' as valid value for OBJECT_MODE (PR #205180)

[Hubert Tong via cfe-commits]

https://github.com/hubert-reinterpretcast commented:

Please update any existing Clang documentation for `OBJECT_MODE` (just search to see if there is any). In either case, please add an update to the release notes before landing the PR.

https://github.com/llvm/llvm-project/pull/205180