[turbofan] Add test to keep generic pipeline on life support.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 36 matching lines @@
 #undef DECLARE_CASE
     case IrOpcode::kBranch:
       // TODO(mstarzinger): If typing is enabled then simplified lowering will
       // have inserted the correct ChangeBoolToBit, otherwise we need to perform
       // poor-man's representation inference here and insert manual change.
       if (!is_typing_enabled_) {
         Node* condition = node->InputAt(0);
         Node* test = graph()->NewNode(machine()->WordEqual(), condition,
                                       jsgraph()->TrueConstant());
         node->ReplaceInput(0, test);
-        break;
       }
       // Fall-through.
     default:
       // Nothing to see.
       return NoChange();
   }
   return Changed(node);
 }
 
 
@@ skipping 703 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8