The Global Load IC doesn't yet play well with --vector-ics.

Until this is addressed, we can simply use the regular IC, as we do
in times of serialization.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/974853002

Cr-Commit-Position: refs/heads/master@{#26977}

src/full-codegen.cc

@@ -442,7 +442,10 @@ void FullCodeGenerator::CallLoadIC(ContextualMode contextual_mode,
 
 
 void FullCodeGenerator::CallGlobalLoadIC(Handle<String> name) {
-  if (masm()->serializer_enabled()) return CallLoadIC(CONTEXTUAL);
+  if (masm()->serializer_enabled() || FLAG_vector_ics) {
+    // Vector-ICs don't work with LoadGlobalIC.
+    return CallLoadIC(CONTEXTUAL);
+  }
   Handle<Code> ic = CodeFactory::LoadGlobalIC(
                         isolate(), isolate()->global_object(), name).code();
   CallIC(ic, TypeFeedbackId::None());

src/ic/ic.cc

@@ -951,6 +951,9 @@ Handle<Code> LoadIC::initialize_stub(Isolate* isolate,
 
 Handle<Code> LoadIC::load_global(Isolate* isolate, Handle<GlobalObject> global,
                                  Handle<String> name) {
+  // This special IC doesn't work with vector ics.
+  DCHECK(!FLAG_vector_ics);
+
   Handle<ScriptContextTable> script_contexts(
       global->native_context()->script_context_table());