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

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 1c8bbbe28d05654e4d39de8d664e1d5fa17b9998..ad5f23e4bcbd225016a448bcbd95fee7eaaaed69 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -143,14 +143,7 @@ bool LCodeGen::GeneratePrologue() {
   if (NeedsEagerFrame()) {
     ASSERT(!frame_is_built_);
     frame_is_built_ = true;
-    __ push(rbp);  // Caller's frame pointer.
-    __ movq(rbp, rsp);
-    __ push(rsi);  // Callee's context.
-    if (info()->IsStub()) {
-      __ Push(Smi::FromInt(StackFrame::STUB));
-    } else {
-      __ push(rdi);  // Callee's JS function.
-    }
+    __ Prologue(info()->IsStub());
     info()->AddNoFrameRange(0, masm_->pc_offset());
   }