Introduce the notion of function addresses in Subzero.

src/IceDefs.h

 //===- subzero/src/IceDefs.h - Common Subzero declaraions -------*- 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 various useful types and classes that have
@@ skipping 22 matching lines @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace Ice {
 
 class Cfg;
 class CfgNode;
 class Constant;
 class GlobalContext;
+class GlobalAddress;
 class Inst;
 class InstPhi;
 class InstTarget;
 class LiveRange;
 class Liveness;
 class Operand;
 class TargetLowering;
 class Variable;
 class VariablesMetadata;
 
@@ skipping 48 matching lines @@
   IceV_All = ~IceV_None,
   IceV_Most = IceV_All & ~IceV_LinearScan
 };
 typedef uint32_t VerboseMask;
 
 typedef llvm::raw_ostream Ostream;
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H