Merge patch from JeremyF:

39-lock-prefix

Add a new UInstr LOCK to represent a "lock" prefix in the instruction
stream. This has the same semantics as NOP, but allows a skin to tell
whether a group of UInstrs associated with an x86 instruction are
meant to be locked.

HELGRIND: uses the LOCK UInstr to automatically take and release a
special __BUS_HARDWARE_LOCK__ around locked instructions. This only
works properly if all instructions touching a given address are locked
(even reads).


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1310 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/vg_skin.h b/include/vg_skin.h
index 540fe5f..10f70e7 100644
--- a/include/vg_skin.h
+++ b/include/vg_skin.h
@@ -492,6 +492,8 @@
    enum {
       NOP,         /* Null op */
 
+      LOCK,	   /* Indicate the existance of a LOCK prefix (functionally NOP) */
+
       /* Moving values around */
       GET,  PUT,   /* simulated register <--> TempReg */
       GETF, PUTF,  /* simulated %eflags  <--> TempReg */