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

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

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

Approved by: re (implicit)

Do not include <sys/ptrace.h> if we're building a cross-debugger, ptrace isn't
used anyway, and it breaks the build, since sys/ptrace.h now includes
<machine/reg.h>

Approved by: re

Add thread support for arm.

MFC After: 1 week

Architecture specific portions of gdb for arm.

Submitted by: cognet@