[Bug preprocessor/71681] header.gcc file lookup is broken for -remap

[andris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71681

--- Comment #3 from Andris Pavenis <andris at gcc dot gnu.org> ---
Patch in mailing list

https://gcc.gnu.org/ml/gcc-patches/2016-09/msg00395.html