Subzero: Add -Wshadow to the build.

src/IceThreading.h

 //===- subzero/src/IceThreading.h - Threading functions ---------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares threading-related functions.
@@ skipping 36 matching lines @@
 // MaxStaticSize, where the queue boundaries are denoted by the Front
 // and Back fields.  Front==Back indicates an empty queue.
 template <typename T, size_t MaxStaticSize = 128>
 class BoundedProducerConsumerQueue {
   BoundedProducerConsumerQueue() = delete;
   BoundedProducerConsumerQueue(const BoundedProducerConsumerQueue &) = delete;
   BoundedProducerConsumerQueue &
   operator=(const BoundedProducerConsumerQueue &) = delete;
 
 public:
-  BoundedProducerConsumerQueue(bool Sequential, size_t MaxSize = MaxStaticSize)
-      : MaxSize(std::min(MaxSize, MaxStaticSize)), Sequential(Sequential) {}
+  BoundedProducerConsumerQueue(bool MySequential,
+                               size_t MyMaxSize = MaxStaticSize)
+      : MaxSize(std::min(MyMaxSize, MaxStaticSize)), Sequential(MySequential) {}
   void blockingPush(T *Item) {
     {
       std::unique_lock<GlobalLockType> L(Lock);
       // If the work queue is already "full", wait for a consumer to
       // grab an element and shrink the queue.
       Shrunk.wait(L, [this] { return size() < MaxSize || Sequential; });
       push(Item);
     }
     GrewOrEnded.notify_one();
   }
@@ skipping 129 matching lines @@
   const uint32_t Sequence;
   const ItemKind Kind;
   std::unique_ptr<VariableDeclarationList> GlobalInits;
   std::unique_ptr<Assembler> Function;
   std::unique_ptr<Cfg> RawFunc;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETHREADING_H