Unsafe.compareAndSwapLong() intrinsic for x86.

Change-Id: Idbc5371a62dfdd84485a657d4548990519200205
diff --git a/compiler/dex/compiler_enums.h b/compiler/dex/compiler_enums.h
index 56facfd..d73f148 100644
--- a/compiler/dex/compiler_enums.h
+++ b/compiler/dex/compiler_enums.h
@@ -374,6 +374,7 @@
   kRegUseA,
   kRegUseC,
   kRegUseD,
+  kRegUseB,
   kRegUseFPCSList0,
   kRegUseFPCSList2,
   kRegUseList0,