[clang] [llvm] [FMV] Rectify incomplete ExtensionInfo entries in TargetParser. (PR #89106)

[Alexandros Lamprineas via llvm-commits]

labrinea wrote:

This has become outdated after the recent tablegen refactoring. I'll rethink about it after https://github.com/llvm/llvm-project/pull/92882 lands

https://github.com/llvm/llvm-project/pull/89106