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

src/ppc/macro-assembler-ppc.h

Index: src/ppc/macro-assembler-ppc.h
diff --git a/src/ppc/macro-assembler-ppc.h b/src/ppc/macro-assembler-ppc.h
index 2ff613db783fd877c78fb42be262eacd0f728611..13d0b9c10013ccde034742417fe7c1d201834d2c 100644
--- a/src/ppc/macro-assembler-ppc.h
+++ b/src/ppc/macro-assembler-ppc.h
@@ -250,6 +250,11 @@ 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, Register dst,
                          LinkRegisterStatus lr_status, SaveFPRegsMode save_fp);