Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

This commit was generated by cvs2svn to compensate for changes in r161537,
which included commits to RCS files with non-trunk default branches.

Import files needed for PowerPC support and not included in the
original GDB 6.1.1 import.