Better support for 'polymorphic' JS and external arrays

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 9be4ca093d185761431f575ad0e49a49137d8fa0..8996537d3dff3f594fe78cc8130d32a993db6d86 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -578,6 +578,7 @@ class MacroAssembler: public Assembler {
                 Label* fail,
                 SmiCheckType smi_check_type);
 
+
   void CheckMap(Register obj,
                 Register scratch,
                 Heap::RootListIndex index,
@@ -585,6 +586,16 @@ class MacroAssembler: public Assembler {
                 SmiCheckType smi_check_type);
 
 
+  // Check if the map of an object is equal to a specified map and branch to a
+  // specified target if equal. Skip the smi check if not required (object is
+  // known to be a heap object)
+  void DispatchMap(Register obj,
+                   Register scratch,
+                   Handle<Map> map,
+                   Handle<Code> success,
+                   SmiCheckType smi_check_type);
+
+
   // Compare the object in a register to a value from the root list.
   // Uses the ip register as scratch.
   void CompareRoot(Register obj, Heap::RootListIndex index);