Add complete ElementKind information directly to Map for objects with elements.

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index bc20eb1de2ad2e6831d1f51cae22ee82637ab948..a133c38ebf6979df03354af0bbfb80e4a34c77cb 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -576,6 +576,12 @@ class MacroAssembler: public Assembler {
                            InstanceType type);
 
 
+  // Check if a map for a JSObject indicates that the object has fast elements.
+  // Jump to the specified label if it does not.
+  void CheckFastElements(Register map,
+                         Register scratch,
+                         Label* fail);
+
   // Check if the map of an object is equal to a specified map (either
   // given directly or as an index into the root list) and branch to
   // label if not. Skip the smi check if not required (object is known