A64: Implement pre-aging support for A64.

src/a64/macro-assembler-a64.h

Index: src/a64/macro-assembler-a64.h
diff --git a/src/a64/macro-assembler-a64.h b/src/a64/macro-assembler-a64.h
index 5c9475c9979ed4e982857986b1b0aa8b3257fc88..42bfba6c600c0674093a564dbf1f2013e7e04b87 100644
--- a/src/a64/macro-assembler-a64.h
+++ b/src/a64/macro-assembler-a64.h
@@ -1945,7 +1945,7 @@ class MacroAssembler : public Assembler {
   //
   // This function takes an Assembler so it can be called from either a
   // MacroAssembler or a PatchingAssembler context.
-  static void EmitFrameSetupForCodeAgePatching(Assembler * assm);
+  static void EmitFrameSetupForCodeAgePatching(Assembler* assm);
 
   // Call EmitFrameSetupForCodeAgePatching from a MacroAssembler context.
   void EmitFrameSetupForCodeAgePatching();
@@ -1954,13 +1954,13 @@ class MacroAssembler : public Assembler {
   // generated by this sequence is expected to replace the code generated by
   // EmitFrameSetupForCodeAgePatching, and represents an old function.
   //
-  // It never makes sense to call this other than in a patching context, so this
-  // method only accepts a PatchingAssembler.
-  //
   // If stub is NULL, this function generates the code age sequence but omits
   // the stub address that is normally embedded in the instruction stream. This
   // can be used by debug code to verify code age sequences.
-  static void EmitCodeAgeSequence(PatchingAssembler * assm, Code * stub);
+  static void EmitCodeAgeSequence(Assembler* assm, Code* stub);
+
+  // Call EmitCodeAgeSequence from a MacroAssembler context.
+  void EmitCodeAgeSequence(Code* stub);
 
   // Return true if the sequence is a young sequence geneated by
   // EmitFrameSetupForCodeAgePatching. Otherwise, this method asserts that the