Add a goto instruction to the IL use it to terminate basic blocks.

vm/flow_graph_builder.h

Index: vm/flow_graph_builder.h
===================================================================
--- vm/flow_graph_builder.h	(revision 9252)
+++ vm/flow_graph_builder.h	(working copy)
@@ -114,9 +114,13 @@
 
   // Append a graph fragment to this graph.  Assumes this graph is open.
   void Append(const EffectGraphVisitor& other_fragment);
-  // Append a single instruction.  Assumes this graph is open.
+  // Append a single instruction.  Assumes this graph is open. Can not be a
+  // block entry instruction.
   void AddInstruction(Instruction* instruction);
 
+  // Append a new block entry to the graph.
+  void AddBlockEntry(BlockEntryInstr* successor);
+
   // Append a 'diamond' branch and join to this graph, depending on which
   // parts are reachable.  Assumes this graph is open.
   void Join(const TestGraphVisitor& test_fragment,