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

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index 13c0e4441649327a7183c1ec586be124eb4bc207..60f529003006afcf45981e2042229401b2729621 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -826,6 +826,39 @@ CODE_AGE_LIST(DEFINE_CODE_AGE_BUILTIN_GENERATOR)
 #undef DEFINE_CODE_AGE_BUILTIN_GENERATOR
 
 
+void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
+  // For now, as in GenerateMakeCodeYoungAgainCommon, we are relying on the fact
+  // that make_code_young doesn't do any garbage collection which allows us to
+  // save/restore the registers without worrying about which of them contain
+  // pointers.
+
+  // The following registers must be saved and restored when calling through to
+  // the runtime:
+  //   r0 - contains return address (beginning of patch sequence)
+  //   r1 - isolate
+  FrameScope scope(masm, StackFrame::MANUAL);
+  __ stm(db_w, sp, r0.bit() | r1.bit() | fp.bit() | lr.bit());
+  __ PrepareCallCFunction(1, 0, r2);
+  __ mov(r1, Operand(ExternalReference::isolate_address(masm->isolate())));
+  __ CallCFunction(ExternalReference::get_mark_code_as_executed_function(
+        masm->isolate()), 2);
+  __ ldm(ia_w, sp, r0.bit() | r1.bit() | fp.bit() | lr.bit());
+
+  // Perform prologue operations usually performed by the young code stub.
+  __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
+  __ add(fp, sp, Operand(2 * kPointerSize));
+
+  // Jump to point after the code-age stub.
+  __ add(r0, r0, Operand(kNoCodeAgeSequenceLength * Assembler::kInstrSize));
+  __ mov(pc, r0);
+}
+
+
+void Builtins::Generate_MarkCodeAsExecutedTwice(MacroAssembler* masm) {
+  GenerateMakeCodeYoungAgainCommon(masm);
+}
+
+
 void Builtins::Generate_NotifyStubFailure(MacroAssembler* masm) {
   {
     FrameScope scope(masm, StackFrame::INTERNAL);