This creates a new version of the FreeBSD core file note generation
logic in the new target-dependent file "fbsd-tdep.c". The new version
is mostly copied from "fbsd-nat.c", but uses the iterator instead of
regset_from_core_section and defines fbsd_make_corefile_notes as a
gdbarch method instead of a target method.
Consecutive architecture-dependent changes exploit the new version,
migrating away from the target method. When all FreeBSD targets are
changed, the target method can go away.
gdb/ChangeLog:
* fbsd-tdep.c: New file.
* fbsd-tdep.h: New file.
* Makefile.in (ALL_TARGET_OBS): Add fbsd-tdep.o.
(HFILES_NO_SRCDIR): Add fbsd-tdep.h.
(ALLDEPFILES): Add fbsd-tdep.c.
