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)

LO_ENROLLPEND is no more existing so just axe it (it was left out by the
original commit axing it).

Forced commit to note that these files were repo copied.

Instead of detecting if lock is already initialized based on standard 1 bit
check, use more accurate 13 bits check. We had too many false-positives with
the standard check.

Reported by: mlaier