allow gcc .... /full/path/to/libfoo.a

gccld would barf if you tried to specify the full pathname of an archive
on the command line to gcc, (e.g., instead of gcc ... -L/full/path/to -lFOO
you say gcc ... /full/path/to/libFOO.a) which many GNU Makefiles try to do.
This patch fixes that.

Ok to commit?

Ok to commit?

Looks great, go for it.

BTW, it would be better to keep bug reports and proposed patches to the
llvmbugs@cs.uiuc.edu list, which helps keep llvmdev traffic down for
people who aren't interested in day-to-day patches and stuff.

Thanks Brian!

-Chris