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)

RTLD support for powerpc64. A few small modifications to the Makefile
and symbol map are required to support various consequences of the dot
symbol scheme:

- Symbols beginning with a dot are reserved, so start private symbols with
an underscore.
- In order to set RTLD breakpoints, gdb must be able to locate the text
entry point, not the data section function descriptor, so add
.r_debug_state to the symbol map on powerpc64.

Obtained from: projects/ppc64

rtld support for PowerPC. Mostly obtained from NetBSD, with mods
for binutils 2.13

Reviewed by: benno

Approved by: re (blanket)