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

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 20c56226e8cca27078e518d32fb357ecd1e5b49b..7fcc59187cb1db6f3d3a60448b089898797a12cc 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -152,10 +152,21 @@ void FullCodeGenerator::Generate() {
   FrameScope frame_scope(masm_, StackFrame::MANUAL);
 
   info->set_prologue_offset(masm_->pc_offset());
-  __ push(rbp);  // Caller's frame pointer.
-  __ movq(rbp, rsp);
-  __ push(rsi);  // Callee's context.
-  __ push(rdi);  // Callee's JS Function.
+  {
+    PredictableCodeSizeScope predictible_code_size_scope(
+        masm_, kNoCodeAgeSequenceLength);
+    if (FLAG_optimize_for_size && FLAG_age_code) {
+        // Pre-age the code.
+      __ Call(isolate()->builtins()->MarkCodeAsExecutedOnce(),
+             RelocInfo::CODE_AGE_SEQUENCE);
+      __ Nop(kNoCodeAgeSequenceLength - Assembler::kShortCallInstructionLength);
+    } else {
+      __ push(rbp);  // Caller's frame pointer.
+      __ movq(rbp, rsp);
+      __ push(rsi);  // Callee's context.
+      __ push(rdi);  // Callee's JS Function.
+    }
+  }
   info->AddNoFrameRange(0, masm_->pc_offset());
 
   { Comment cmnt(masm_, "[ Allocate locals");
@@ -171,7 +182,6 @@ void FullCodeGenerator::Generate() {
       }
     }
   }
-
   bool function_in_register = true;
 
   // Possibly allocate a local context.
@@ -190,6 +200,7 @@ void FullCodeGenerator::Generate() {
       __ CallRuntime(Runtime::kNewFunctionContext, 1);
     }
     function_in_register = false;
+
     // Context is returned in both rax and rsi.  It replaces the context
     // passed to us.  It's saved in the stack and kept live in rsi.
     __ movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);