First pass at emitIAS for branches and binding labels

src/assembler.h

 //===- subzero/src/assembler.h - Integrated assembler -----------*- C++ -*-===//
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        The Subzero Code Generator
@@ skipping 189 matching lines @@
 
   friend class AssemblerFixup;
 };
 
 class Assembler {
   Assembler(const Assembler &) = delete;
   Assembler &operator=(const Assembler &) = delete;
 
 public:
   Assembler() {}
-  ~Assembler() {}
+  virtual ~Assembler() {}
 
   // Allocate a chunk of bytes using the per-Assembler allocator.
   uintptr_t AllocateBytes(size_t bytes) {
     // For now, alignment is not related to NaCl bundle alignment, since
     // the buffer's GetPosition is relative to the base. So NaCl bundle
     // alignment checks can be relative to that base. Later, the buffer
     // will be copied out to a ".text" section (or an in memory-buffer
     // that can be mprotect'ed with executable permission), and that
     // second buffer should be aligned for NaCl.
     const size_t Alignment = 16;
     return reinterpret_cast<uintptr_t>(Allocator.Allocate(bytes, Alignment));
   }
 
+  virtual void BindCfgNodeLabel(SizeT NodeNumber) = 0;
+
   // Allocate data of type T using the per-Assembler allocator.
   template <typename T> T *Allocate() { return Allocator.Allocate<T>(); }
 
 private:
   llvm::BumpPtrAllocator Allocator;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ASSEMBLER_H_