Refactor use of Isolate::use_crankshaft.

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 0a7221344baebf3b6f8c57824aaf3446af301bda..bd6182a93d54035feb54bd35f4636203abd0e692 100644
--- a/src/runtime/runtime-test.cc
+++ b/src/runtime/runtime-test.cc
@@ -60,6 +60,8 @@ RUNTIME_FUNCTION(Runtime_OptimizeFunctionOnNextCall) {
                  (function->code()->kind() == Code::FUNCTION &&
                   function->code()->optimizable()));
 
+  if (!isolate->use_crankshaft()) return isolate->heap()->undefined_value();
+
   // If the function is optimized, just return.
   if (function->IsOptimized()) return isolate->heap()->undefined_value();