Add codegen support to the optimizing compiler.

Change-Id: I9aae76908ff1d6e64fb71a6718fc1426b67a5c28
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index e6db7bc..f78e56b 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -29,6 +29,8 @@
   entry_block_->AddInstruction(new (arena_) HGoto());
   exit_block_ = new (arena_) HBasicBlock(graph_);
   exit_block_->AddInstruction(new (arena_) HExit());
+  graph_->set_entry_block(entry_block_);
+  graph_->set_exit_block(exit_block_);
 
   // To avoid splitting blocks, we compute ahead of time the instructions that
   // start a new block, and create these blocks.