ARM: Add support load/store multiple VFP registers

src/arm/constants-arm.h

Index: src/arm/constants-arm.h
diff --git a/src/arm/constants-arm.h b/src/arm/constants-arm.h
index 0ac567cb11f8ccb3252e1f9d4da8491e6d203d81..3b1b91958e3f022aed698e52c90b4fab6c4ccfc9 100644
--- a/src/arm/constants-arm.h
+++ b/src/arm/constants-arm.h
@@ -346,7 +346,9 @@ enum BlockAddrMode {
   da_x         = (0|0|0) << 21,  // Decrement after.
   ia_x         = (0|4|0) << 21,  // Increment after.
   db_x         = (8|0|0) << 21,  // Decrement before.
-  ib_x         = (8|4|0) << 21   // Increment before.
+  ib_x         = (8|4|0) << 21,  // Increment before.
+
+  kBlockAddrModeMask = (8|4|1) << 21
 };