[compiler] Make SFI "optimize" flag a "tier up" flag

src/builtins/x64/builtins-x64.cc

Index: src/builtins/x64/builtins-x64.cc
diff --git a/src/builtins/x64/builtins-x64.cc b/src/builtins/x64/builtins-x64.cc
index c412431fa5517300596180e2d4713e78e60206ab..0b0cf0d974e59d013b84a03ac12f01c08a8bc958 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -1122,12 +1122,9 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
 
   __ bind(&try_shared);
   __ movp(entry, FieldOperand(closure, JSFunction::kSharedFunctionInfoOffset));
-  // Is the shared function marked for optimization?
-  __ testb(
-      FieldOperand(entry,
-                   SharedFunctionInfo::kWasMarkedForOptimizationByteOffset),
-      Immediate(
-          1 << SharedFunctionInfo::kWasMarkedForOptimizationBitWithinByte));
+  // Is the shared function marked for tier up?
+  __ testb(FieldOperand(entry, SharedFunctionInfo::kMarkedForTierUpByteOffset),
+           Immediate(1 << SharedFunctionInfo::kMarkedForTierUpBitWithinByte));
   __ j(not_zero, &gotta_call_runtime);
   // Is the full code valid?
   __ movp(entry, FieldOperand(entry, SharedFunctionInfo::kCodeOffset));