[debugger] add mixed-stack tests.

src/runtime/runtime-test.cc

Index: src/runtime/runtime-test.cc
diff --git a/src/runtime/runtime-test.cc b/src/runtime/runtime-test.cc
index 36d359712e541066ca24dd8c81cece0be4121909..356c6c771720c27116f0784f1412e2b92a91d543 100644
--- a/src/runtime/runtime-test.cc
+++ b/src/runtime/runtime-test.cc
@@ -140,6 +140,46 @@ RUNTIME_FUNCTION(Runtime_OptimizeFunctionOnNextCall) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_InterpretFunctionOnNextCall) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, function_object, 0);
+  if (!function_object->IsJSFunction()) {
+    return isolate->heap()->undefined_value();
+  }
+  Handle<JSFunction> function = Handle<JSFunction>::cast(function_object);
+
+  // Do not tier down if we are already on optimized code. Replacing optimized
+  // code without actual deoptimization can lead to funny bugs.
+  if (function->code()->kind() != Code::OPTIMIZED_FUNCTION &&
+      function->shared()->HasBytecodeArray()) {
+    function->ReplaceCode(*isolate->builtins()->InterpreterEntryTrampoline());
+  }
+  return isolate->heap()->undefined_value();
+}
+
+RUNTIME_FUNCTION(Runtime_BaselineFunctionOnNextCall) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, function_object, 0);
+  if (!function_object->IsJSFunction()) {
+    return isolate->heap()->undefined_value();
+  }
+  Handle<JSFunction> function = Handle<JSFunction>::cast(function_object);
+
+  // Do not tier down if we are already on optimized code. Replacing optimized
+  // code without actual deoptimization can lead to funny bugs.
+  if (function->code()->kind() != Code::OPTIMIZED_FUNCTION &&
+      function->code()->kind() != Code::FUNCTION) {
+    if (function->shared()->HasBaselineCode()) {
+      function->ReplaceCode(function->shared()->code());
+    } else {
+      function->MarkForBaseline();
+    }
+  }
+
+  return isolate->heap()->undefined_value();
+}
 
 RUNTIME_FUNCTION(Runtime_OptimizeOsr) {
   HandleScope scope(isolate);