Fixes a couple problems with GC of unoptimized code.

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
===================================================================
--- runtime/vm/flow_graph_builder.cc	(revision 30197)
+++ runtime/vm/flow_graph_builder.cc	(working copy)
@@ -3848,7 +3848,9 @@
         new CheckStackOverflowInstr(function.token_pos(), 0);
     // If we are inlining don't actually attach the stack check. We must still
     // create the stack check in order to allocate a deopt id.
-    if (!IsInlining()) for_effect.AddInstruction(check);
+    if (!IsInlining()) {
+      for_effect.AddInstruction(check);
+    }
   }
   parsed_function()->node_sequence()->Visit(&for_effect);
   AppendFragment(normal_entry, for_effect);