Make TestJSArrayForAllocationMemento less awkward.

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 30a617b634823a2a8cb6c3eab73775bc74748a00..c709e5c57f5dcf2600405e7cc6c6c72c0ba909af 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -1388,9 +1388,20 @@ class MacroAssembler: public Assembler {
   // to another type.
   // On entry, receiver_reg should point to the array object.
   // scratch_reg gets clobbered.
-  // If allocation info is present, condition flags are set to eq
+  // If allocation info is present, condition flags are set to eq.
   void TestJSArrayForAllocationMemento(Register receiver_reg,
-                                       Register scratch_reg);
+                                       Register scratch_reg,
+                                       Label* no_memento_found);
+
+  void JumpIfJSArrayHasAllocationMemento(Register receiver_reg,
+                                         Register scratch_reg,
+                                         Label* memento_found) {
+    Label no_memento_found;
+    TestJSArrayForAllocationMemento(receiver_reg, scratch_reg,
+                                    &no_memento_found);
+    b(eq, memento_found);
+    bind(&no_memento_found);
+  }
 
  private:
   void CallCFunctionHelper(Register function,