This includes removing all vestiges of the old not-really supported
ability to build cross tools targeting non-FreeBSD systems, such as
m68k Lynx and NetBSD. Move as much duplicated code from platform
Makefiles into the shared Makefiles. Add a simple mechanism for
specifying ELF 'ldscripts'. Also share as many .h files as possible
(now a single bfd.h vs. one per platform).
(the two may be different (ie, build vs. runtime))
Allow ldscript's SEARCH_DIR do be rooted somewhere other than `/'.
(in this case at TOOLS_PREFIX)
These changes are most helpful during `make buildworld' so that the shared
libs built in the middle of `make buildworld' are used vs. the ones in
/usr/lib on the build machine.
Submitted by: ru