[clang] [Clang] Add resource_dir_EQ flag to CC1Option group (PR #140870)

[Wenju He via cfe-commits]

wenju-he wrote:

> do we know why https://github.com/llvm/llvm-project/blob/main/clang/include/clang/Driver/Options.td#L5894-L5901 doesn't declare _EQ version for cc1?

Git history shows the earliest commit https://github.com/llvm/llvm-project/commit/f3e624ca73b007552554b31358f4abde9eb2d3b7 already have the difference. I don't see obvious reason why resource_dir_EQ should not be cc1 option.

> i think instead of working around this in various places, we should unify the two if possible.

done, thanks for the suggestion.

https://github.com/llvm/llvm-project/pull/140870