[clang] [Clang][ARM] support arm target attribute, and warning for bad typo (PR #74812)

[David Spickett via cfe-commits]

DavidSpickett wrote:

I was mistaken about the `target_link_libraries`, that's what `clangBasic` links to not `clangAST`.

It's possible that `clangBasic` now needs to depend on `clangAST`, assuming cmake and the linker are ok with that.

https://github.com/llvm/llvm-project/pull/74812