Enable preaging of code objects when --optimize-for-size.

src/codegen.cc

Index: src/codegen.cc
diff --git a/src/codegen.cc b/src/codegen.cc
index 7b2f81ba8ab0e3ea85595fd18ec6d3664904e71e..573ddc6ce765af0cf2af2a8e25962a18ead2ed48 100644
--- a/src/codegen.cc
+++ b/src/codegen.cc
@@ -113,12 +113,12 @@ Handle<Code> CodeGenerator::MakeCodeEpilogue(MacroAssembler* masm,
   masm->GetCode(&desc);
   Handle<Code> code =
       isolate->factory()->NewCode(desc, flags, masm->CodeObject(),
-                                  false, is_crankshafted);
+                                  false, is_crankshafted,
+                                  info->prologue_offset());
   isolate->counters()->total_compiled_code_size()->Increment(
       code->instruction_size());
   isolate->heap()->IncrementCodeGeneratedBytes(is_crankshafted,
       code->instruction_size());
-  code->set_prologue_offset(info->prologue_offset());
   return code;
 }