update kernel man pages to document ownlock, getlockpc, and setlockpc.

Reference: /n/atom/patch/applied/manownlock
Date: Sun Jun  8 11:42:18 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/man/9/lock	Sun Jun  8 11:41:49 2014
+++ /sys/man/9/lock	Sun Jun  8 11:41:49 2014
@@ -1,6 +1,6 @@
 .TH LOCK 9
 .SH NAME
-lock, canlock, ilock, iunlock, unlock \- spin locks
+lock, canlock, ilock, iunlock, unlock, ownlock, lockgetpc, locksetpc \- spin locks
 .SH SYNOPSIS
 .ta \w'\fLvoid 'u
 .B
@@ -17,6 +17,15 @@
 .PP
 .B
 void    iunlock(Lock *l)
+.PP
+.B
+int     ownlock(Lock *l)
+.PP
+.B
+uintptr locksetpc(Lock *l, uintptr pc)
+.PP
+.B
+void    lockgetpc(Lock *l)
 .SH DESCRIPTION
 These primitives control access to shared
 resources using spin locks.
@@ -80,6 +89,14 @@
 .I Iunlock
 releases a lock previously got by
 .IR ilock .
+.PP
+.I Ownlock
+returns true if the lock is held on the current processor.
+.I Lockgetpc
+returns the program counter where the current holder of
+the lock acquired the lock.
+.I Locksetpc
+sets the current program counter.
 .SH SOURCE
 .B /sys/src/9/port/taslock.c
 .br