[debugger,interpreter] precisely determine execution tier.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 5ff72651c106a4bdb6eb916f47a8523c60bad098..a629326262070db710ebf4981d9bd3a788623c9d 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -5885,7 +5885,7 @@ DebugInfo* SharedFunctionInfo::GetDebugInfo() {
 
 
 bool SharedFunctionInfo::HasDebugCode() {
-  return HasBytecodeArray() ||
+  return IsInterpreted() ||
          (code()->kind() == Code::FUNCTION && code()->has_debug_break_slots());
 }
 
@@ -5909,6 +5909,15 @@ bool SharedFunctionInfo::HasBytecodeArray() {
   return function_data()->IsBytecodeArray();
 }
 
+bool SharedFunctionInfo::IsInterpreted() {
+  // Currently, having bytecode does not mean the function is actually being
+  // interpreted. However, the debugger has to know precisely what is going to
+  // be executed.
+  // TODO(yangguo,mstarzinger): make this a synonym of HasBytecodeArray().
+  return code() ==
+         GetIsolate()->builtins()->builtin(
+             Builtins::kInterpreterEntryTrampoline);
+}
 
 BytecodeArray* SharedFunctionInfo::bytecode_array() {
   DCHECK(HasBytecodeArray());