[PATCH] D139717: Revert "[Driver] Remove Joined -X"

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added a comment.

> This change is breaking internal builds. We use the -Xfoo pattern but can now no longer manage whether we allow an unused -Xfoo option to pass as a warning or promote it to an error.

Which `-Xfoo` is used? Do your internal builds reserve `-Xfoo` as a placeholder to do other non-upstream work? Then you can consider `-Gfoo` if your builds don't need the mips semantics.
Is it possible to clean up the previously-ignored-with-a-warning `-Xfoo`?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139717/new/

https://reviews.llvm.org/D139717