[debugger] simplify debug stepping.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 1c404365195df213d96051864bae353ebdc0753d..332ac4c6f2e861c52f41595a218a6e9a93d72c2d 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -4998,11 +4998,12 @@ 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());
-  li(t0, Operand(step_in_enabled));
+  ExternalReference last_step_action =
+      ExternalReference::debug_last_step_action_address(isolate());
+  STATIC_ASSERT(StepFrame > StepIn);
+  li(t0, Operand(last_step_action));
   lb(t0, MemOperand(t0));
-  Branch(&skip_flooding, eq, t0, Operand(zero_reg));
+  Branch(&skip_flooding, lt, t0, Operand(StepIn));
   {
     FrameScope frame(this,
                      has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);