Subzero: Make thread_local work under MacOS 10.6.

src/IceCfg.cpp

 //===- subzero/src/IceCfg.cpp - Control flow graph implementation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Cfg class, including constant pool
 // management.
 //
 //===----------------------------------------------------------------------===//
 
 #include "assembler.h"
 #include "IceCfg.h"
 #include "IceCfgNode.h"
 #include "IceClFlags.h"
 #include "IceDefs.h"
 #include "IceELFObjectWriter.h"
 #include "IceInst.h"
 #include "IceLiveness.h"
 #include "IceOperand.h"
 #include "IceTargetLowering.h"
 
 namespace Ice {
 
-thread_local const Cfg *Cfg::CurrentCfg = nullptr;
+ICE_ATTRIBUTE_TLS const Cfg *Cfg::CurrentCfg = nullptr;
 
 ArenaAllocator<> *getCurrentCfgAllocator() {
   return Cfg::getCurrentCfgAllocator();
 }
 
 Cfg::Cfg(GlobalContext *Ctx)
     : Ctx(Ctx), FunctionName(""), ReturnType(IceType_void),
       IsInternalLinkage(false), HasError(false), FocusedTiming(false),
       ErrorMessage(""), Entry(nullptr), NextInstNumber(Inst::NumberInitial),
       Allocator(new ArenaAllocator<>()), Live(nullptr),
@@ skipping 475 matching lines @@
     }
   }
   // Print each basic block
   for (CfgNode *Node : Nodes)
     Node->dump(this);
   if (getContext()->isVerbose(IceV_Instructions))
     Str << "}\n";
 }
 
 } // end of namespace Ice