[turbofan] Don't connect regular Phis into the effect chain.

When the effect control linearizer tries to clone a branch, it
accidentially connected regular Phis into the effect chain.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2146553006
Cr-Commit-Position: refs/heads/master@{#37698}

src/compiler/effect-control-linearizer.cc

@@ -276,8 +276,10 @@ void TryCloneBranch(Node* node, BasicBlock* block, Graph* graph,
         edge.UpdateTo((control == matcher.IfTrue()) ? phi_true : phi_false);
       }
     }
-    true_block_data->current_effect = phi_true;
-    false_block_data->current_effect = phi_false;
+    if (phi->opcode() == IrOpcode::kEffectPhi) {
+      true_block_data->current_effect = phi_true;
+      false_block_data->current_effect = phi_false;
+    }
     phi->Kill();
   }
   // Fix up IfTrue and IfFalse and kill all dead nodes.