Fix missing initialization of last_true_block_ in IfBuilder.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/23976005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16834 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -727,6 +727,7 @@ HGraphBuilder::IfBuilder::IfBuilder(
       captured_(false),
       needs_compare_(false),
       first_true_block_(NULL),
+      last_true_block_(NULL),
       first_false_block_(NULL),
       split_edge_merge_block_(NULL),
       merge_block_(NULL) {