Merge from ../egcs/gcc/gcc.c rev.1.5:

Merge from ../egcs/gcc/gcc.c rev.1.5:
Don't exclude directories that the linker is "known" to search (/lib
and /usr/lib) when deciding whether to pass certain paths to the
linker.  Under FreeBSD, the linker is actually known to never search
/lib and to only search /usr/lib in the elf case.  Not passing the
paths causes at best causes confusing differences for cross compiling.
This change is conditional on FREEBSD_NATIVE but should be absolute.