[clang] [clang-tools-extra] [flang] [llvm] [mlir] [polly] [test]: fix filecheck annotation typos (PR #91854)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> Ideally FileCheck should prefix commands with some tag to distinguish comments from filecheck annotations, like
> `--command-tag=@` and use as `@CHECK: xxx`, `@MYCHECK-NEXT: yyy`, etc. Making typo\error in both prefix and command tag will be harder, i guess. That way tool can immediately fail if can see command tag with unknown prefix\directive, without silently guessing that this is comment and skipping.

I remember I have seen quite a few FileCheck and lit improvement proposals. 
While some have been implemented, others are still under consideration.
You might be interested in some threads that you can find by searching for `FileCheck @jh7370` and `FileCheck @pogo59` on https://discourse.llvm.org/ .


https://github.com/llvm/llvm-project/pull/91854