Reland: Fix bug in field type tracking and polymorphic inlining.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
===================================================================
--- runtime/vm/compiler.cc	(revision 27690)
+++ runtime/vm/compiler.cc	(working copy)
@@ -270,7 +270,9 @@
     LongJump bailout_jump;
     isolate->set_long_jump_base(&bailout_jump);
     if (setjmp(*bailout_jump.Set()) == 0) {
+      FlowGraphBuilder* builder = NULL;
       FlowGraph* flow_graph = NULL;
+      GrowableArray<const Field*> guarded_fields;
       // TimerScope needs an isolate to be properly terminated in case of a
       // LongJump.
       {
@@ -290,11 +292,12 @@
         }
 
         // Build the flow graph.
-        FlowGraphBuilder builder(parsed_function,
-                                 ic_data_array,
-                                 NULL,  // NULL = not inlining.
-                                 osr_id);
-        flow_graph = builder.BuildGraph();
+        builder = new FlowGraphBuilder(parsed_function,
+                                       ic_data_array,
+                                       NULL,  // NULL = not inlining.
+                                       &guarded_fields,
+                                       osr_id);
+        flow_graph = builder->BuildGraph();
       }
 
       if (FLAG_print_flow_graph ||
@@ -326,13 +329,12 @@
       // Collect all instance fields that are loaded in the graph and
       // have non-generic type feedback attached to them that can
       // potentially affect optimizations.
-      GrowableArray<const Field*> guarded_fields(10);
       if (optimized) {
         TimerScope timer(FLAG_compiler_stats,
                          &CompilerStats::graphoptimizer_timer,
                          isolate);
 
-        FlowGraphOptimizer optimizer(flow_graph, &guarded_fields);
+        FlowGraphOptimizer optimizer(flow_graph);
         optimizer.ApplyICData();
         DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
@@ -358,7 +360,7 @@
           optimizer.ApplyClassIds();
           DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
-          FlowGraphInliner inliner(flow_graph, &guarded_fields);
+          FlowGraphInliner inliner(flow_graph);
           inliner.Inline();
           // Use lists are maintained and validated by the inliner.
           DEBUG_ASSERT(flow_graph->VerifyUseLists());