[clang] [flang] [clang][driver] When -fveclib=ArmPL flag is in use, always link against libamath (PR #116432)

[Paul Osmialowski via cfe-commits]

pawosm-arm wrote:

> Typo in PR title `flang` -> `flag`

Corrected both the title and the commit message. Thanks for spotting this!

https://github.com/llvm/llvm-project/pull/116432