Unsafe.compareAndSwapLong() intrinsic for x86.

Change-Id: Idbc5371a62dfdd84485a657d4548990519200205
diff --git a/compiler/dex/quick/mir_to_lir.h b/compiler/dex/quick/mir_to_lir.h
index 92e21ff..9d35667 100644
--- a/compiler/dex/quick/mir_to_lir.h
+++ b/compiler/dex/quick/mir_to_lir.h
@@ -71,6 +71,7 @@
 #define REG_USEA             (1ULL << kRegUseA)
 #define REG_USEC             (1ULL << kRegUseC)
 #define REG_USED             (1ULL << kRegUseD)
+#define REG_USEB             (1ULL << kRegUseB)
 #define REG_USE_FPCS_LIST0   (1ULL << kRegUseFPCSList0)
 #define REG_USE_FPCS_LIST2   (1ULL << kRegUseFPCSList2)
 #define REG_USE_LIST0        (1ULL << kRegUseList0)