[libcxx-commits] [libcxx] [libcxx][docs] Make test name pattern documentation more obvious (PR #73136)

[Will Hawkins via libcxx-commits]

hawkinsw wrote:

> > The other thing that I would like to add with this PR is documentation on the actual commands available in the lit built-in shell tests.
> 
> Which commands do you mean? The actual builtin Lit ShTest commands like `RUN`? If so, those are already documented in Lit-specific documentation. We should move the documentation for the commands we add in our test format (like `ADDITIONAL_COMPILE_FLAGS`), though.

I have added documentation for the `ADDITIONAL_COMPILE_FLAGS` and `FILE_DEPENDENCIES` directives.

https://github.com/llvm/llvm-project/pull/73136