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)

The END() must expand to the .endp directive with the same name as
on the corresponding .proc directive, or the .endp must not have a
name at all.
While here, remove an artificial dependency in Ovfork.S by performing
manual register renaming.

Use __FBSDID.

Fix a load of dependancy violations.

Clean up syscall generation in libc by removing HIDDEN_SYSCALLS
and treating (almost) all system calls the same way:

__sys_foo - actual syscall
foo, _foo - weak definitions to __sys_foo

Change PSEUDO syscalls (currently only _exit and _getlogin) to
be __sys_foo (T) and _foo (W).

Add $FreeBSD$ to a few files to satisfy commitprep.

Suggested by: bde

Fix RAW dependency violation on p6 between cmp and mov.

Initial libc port for ia64.