Make sure IfBuilder::Return clears the current block.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index f8771d11b1bc36be311f1c02a6987d5d3269f084..2d1e844ecc37c565004575764d88af7554bb83a9 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -822,9 +822,10 @@ void HGraphBuilder::IfBuilder::Deopt() {
 
 void HGraphBuilder::IfBuilder::Return(HValue* value) {
   HBasicBlock* block = builder_->current_block();
-  block->Finish(new(zone()) HReturn(value,
-                                    builder_->environment()->LookupContext(),
-                                    builder_->graph()->GetConstantMinus1()));
+  HValue* context = builder_->environment()->LookupContext();
+  HValue* parameter_count = builder_->graph()->GetConstantMinus1();
+  block->FinishExit(new(zone()) HReturn(value, context, parameter_count));
+  builder_->set_current_block(NULL);
   if (did_else_) {
     first_false_block_ = NULL;
   } else {