Implement function proxies (except for their use as constructors).

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 9c653adbbaebfd76c50cecbce5220b59492d0c0b..2951cb54dbb321c9fd64d4f77b8ec25df053fa3b 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -586,9 +586,7 @@ class MacroAssembler: public Assembler {
 
   // Compare instance type in a map.  map contains a valid map object whose
   // object type should be compared with the given type.  This both
-  // sets the flags and leaves the object type in the type_reg register.  It
-  // leaves the heap object in the heap_object register unless the heap_object
-  // register is the same register as type_reg.
+  // sets the flags and leaves the object type in the type_reg register.
   void CompareInstanceType(Register map,
                            Register type_reg,
                            InstanceType type);