build failure, gcc4 merged over Binutils 2.15.97

[Don Lindsay]

Just a head's-up for anyone with build scripts resembling mine.

I use a merged-source build, ie I use two "cpio -pdlmu" invocations to
merge the binutils and gcc sources, then I do a single
configure/build/install. (Actually, it's 3 cpio's: I also merge in
newlib.)

Merging binutils-2.15.97 over gcc-4.0.0-20050417 (AKA GCC-4 RC2)  works. A
GCC bootstrap on x86/Red Hat Linux 7.3 went fine. A linux X MIPS64 cross
compiler also built OK.

Merging the other way (gcc over binutils) broke. Specifically,
include/libiberty.h in binutils contains

	extern int unlink_if_ordinary PARAMS((const char *));

and that line is needed, so the include/libiberty.h in GCC won't do.

-- 
Don