Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r251212, r251480:

GCC: bring back experimental support for amdfam10/barcelona CPUs.

This is a revised subset of the support initially brought in in r236962
and later reverted. The collateral efects seem to have disappeared but
it is still recommended to set the CPUTYPE with caution.

While here also install AMD intrinsics header ammintrin.h

Reviewed by: jkim (ages ago)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Fix -march/-mtune=native autodetection for Intel Core 2 CPUs

Obtained from: gcc 4.3 (partial rev. 119454; GPLv2)
MFC after: 2 weeks

This commit was generated by cvs2svn to compensate for changes in r169689,
which included commits to RCS files with non-trunk default branches.

GCC 4.2.0 release.