[debugger] flood function for stepping before calling it.

src/debug/debug.h

Index: src/debug/debug.h
diff --git a/src/debug/debug.h b/src/debug/debug.h
index d8e7596a9b53dca5319a0a0a4d2c5258273f7846..097a91536554f416df45690983c91f7ff5924b6f 100644
--- a/src/debug/debug.h
+++ b/src/debug/debug.h
@@ -31,7 +31,7 @@ class DebugScope;
 
 
 // Step actions. NOTE: These values are in macros.py as well.
-enum StepAction {
+enum StepAction : int8_t {
   StepNone = -1,  // Stepping not prepared.
   StepOut = 0,    // Step out of the current function.
   StepNext = 1,   // Step to the next statement in the current function.
@@ -502,8 +502,8 @@ class Debug {
     return reinterpret_cast<Address>(address);
   }
 
-  Address step_in_fp_addr() {
-    return reinterpret_cast<Address>(&thread_local_.step_into_fp_);
+  Address last_step_action_addr() {
+    return reinterpret_cast<Address>(&thread_local_.last_step_action_);
   }
 
   StepAction last_step_action() { return thread_local_.last_step_action_; }