Fixes a couple problems with GC of unoptimized code.

runtime/vm/flow_graph_builder.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 3830 matching lines @@
                            CatchClauseNode::kInvalidTryIndex);
   graph_entry_ = new GraphEntryInstr(parsed_function(), normal_entry, osr_id_);
   EffectGraphVisitor for_effect(this);
   // This check may be deleted if the generated code is leaf.
   // Native functions don't need a stack check at entry.
   if (!function.is_native()) {
     CheckStackOverflowInstr* check =
         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);
   // Check that the graph is properly terminated.
   ASSERT(!for_effect.is_open());
 
   // When compiling for OSR, use a depth first search to prune instructions
   // unreachable from the OSR entry.  Catch entries are not (yet) properly
   // recognized as reachable.
   if (osr_id_ != Isolate::kNoDeoptId) {
@@ skipping 23 matching lines @@
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart