Fix the loop-builder to tag the entire body as part of the loop.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 7e20aafb55825ac11de76f3b503fca0f08fcb1ff..86c6a0594a0a5cfca34d75467658a7607bb24f6a 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -957,8 +957,9 @@ void HGraphBuilder::LoopBuilder::EndBody() {
 
   // Push the new increment value on the expression stack to merge into the phi.
   builder_->environment()->Push(increment_);
-  builder_->current_block()->GotoNoSimulate(header_block_);
-  header_block_->loop_information()->RegisterBackEdge(body_block_);
+  HBasicBlock* last_block = builder_->current_block();
+  last_block->GotoNoSimulate(header_block_);
+  header_block_->loop_information()->RegisterBackEdge(last_block);
 
   builder_->set_current_block(exit_block_);
   // Pop the phi from the expression stack