Drop the `Separate` form of `-fmodule-name X`, `-fprofile-remapping-file X`, and `-frewrite-map-file X`.
To the best of my knowledge they are not used. Their conventional Joined forms (`-fFOO=`) should be used instead.
`-fdebug-compilation-dir X` is used in several places, e.g. chromium/infra/goma.
It is also advertised in http://blog.llvm.org/2019/11/deterministic-builds-with-clang-and-lld.html
So we keep it but make the EQ form canonical and the Separate form an alias.
Differential Revision: https://reviews.llvm.org/D96886
Avoid failing in the backend when the rewrite map does not exist. Rather check
that the map exists in the frontend before handing it off to the backend. Add
the missing rewrite maps that the tests were referencing.
llvm-svn: 282379
Fangrui Song