[debugger] simplify debug stepping.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 8f8e7fc3bec4373cc086fadc504a6e1b595c6653..d095b3ae9b6f5b83596dd6b0f364b47e21c8f80a 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -4338,11 +4338,12 @@ void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
                                              const ParameterCount& expected,
                                              const ParameterCount& actual) {
   Label skip_flooding;
-  ExternalReference step_in_enabled =
-      ExternalReference::debug_step_in_enabled_address(isolate());
-  Operand step_in_enabled_operand = ExternalOperand(step_in_enabled);
-  cmpb(step_in_enabled_operand, Immediate(0));
-  j(equal, &skip_flooding);
+  ExternalReference last_step_action =
+      ExternalReference::debug_last_step_action_address(isolate());
+  Operand last_step_action_operand = ExternalOperand(last_step_action);
+  STATIC_ASSERT(StepFrame > StepIn);
+  cmpb(last_step_action_operand, Immediate(StepIn));
+  j(less, &skip_flooding);
   {
     FrameScope frame(this,
                      has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);