Harden OptimizeFunctionOnNextCall.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index f0c5edc53b1e8947646ddac4420a27a65d8149e9..7ff15ec69ee059c572f9c2b6507c1d012078df91 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -8632,7 +8632,14 @@ RUNTIME_FUNCTION(Runtime_OptimizeFunctionOnNextCall) {
   HandleScope scope(isolate);
   RUNTIME_ASSERT(args.length() == 1 || args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
-
+  // The following two assertions are lifted from the DCHECKs inside
+  // JSFunction::MarkForOptimization().
+  RUNTIME_ASSERT(!function->shared()->is_generator());
+  RUNTIME_ASSERT(function->shared()->allows_lazy_compilation() ||
+                 (function->code()->kind() == Code::FUNCTION &&
+                  function->code()->optimizable()));
+
+  // If the function is optimized, just return.
   if (function->IsOptimized()) return isolate->heap()->undefined_value();
 
   function->MarkForOptimization();