[clang] [flang] [flang] Update -falias-analysis help text (PR #73548)

[Tom Eccles via cfe-commits]

tblah wrote:

Closing this because I decided to just remove the `-f[no-]alias-analysis` flags instead. https://github.com/llvm/llvm-project/pull/74343

https://github.com/llvm/llvm-project/pull/73548