[Bug gcov-profile/93401] [9/10 regression] It is no longer possible to use -fprofile-generate= on setups with different instrumentation and feedback directories

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93401

--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Actually passing phony / is not needed. We could do right thing with 

gcc foo.c -o <buildir>/ibb1/foo.o -fprofile-prefix-map=<buildir>=
-fprofile-generate

or

gcc foo.c -o <buildir>/ibb1/foo.o -fprofile-strip-prefix=<buildir>
-fprofile-generate

if we do not like the map infrastructure