Start adding an integrated assembler.

src/IceCfg.h

Index: src/IceCfg.h
diff --git a/src/IceCfg.h b/src/IceCfg.h
index e12bc9de0a77626817f960e86c2a3356ba879433..27a254a00661963f134914fdf2d542858bf88452 100644
--- a/src/IceCfg.h
+++ b/src/IceCfg.h
@@ -17,6 +17,9 @@
 
 #include "IceDefs.h"
 #include "IceTypes.h"
+
+#include "assembler.h"
+#include "IceClFlags.h"
 #include "IceGlobalContext.h"
 
 #include "llvm/ADT/OwningPtr.h"
@@ -74,6 +77,12 @@ public:
   // Miscellaneous accessors.
   TargetLowering *getTarget() const { return Target.get(); }
   Liveness *getLiveness() const { return Live.get(); }
+  template <typename T> T *getAssembler() const {
+    return static_cast<T *>(TargetAssembler.get());
+  }
+  bool UseIntegratedAssembler() const {
+    return getContext()->getFlags().UseIntegratedAssembler;
+  }
   bool hasComputedFrame() const;
 
   // Passes over the CFG.
@@ -150,6 +159,7 @@ private:
   VarList Args; // subset of Variables, in argument order
   llvm::OwningPtr<Liveness> Live;
   llvm::OwningPtr<TargetLowering> Target;
+  llvm::OwningPtr<Assembler> TargetAssembler;
 
   // CurrentNode is maintained during dumping/emitting just for
   // validating Variable::DefNode.  Normally, a traversal over