Write barrier for storing a code entry, and usage in CompileLazy builtin.

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 c77e848b63940bdfc2043e4e8489fe6fa93a07f6..e837f9ce0f70c6efcfdc3a8eca7fd73b1a6c35e5 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -290,6 +290,11 @@ class MacroAssembler: public Assembler {
                      pointers_to_here_check_for_value);
   }
 
+  // Notify the garbage collector that we wrote a code entry into a
+  // JSFunction. Only scratch is clobbered by the operation.
+  void RecordWriteCodeEntryField(Register js_function, Register code_entry,
+                                 Register scratch);
+
   void RecordWriteForMap(
       Register object,
       Register map,