Add initial integrated assembler w/ some Xmm ops.

src/IceCfg.cpp

Index: src/IceCfg.cpp
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index 44393230daf345055f2853f0c465ef58ebb9be81..e16e8ffa390b9550a4f024b7b3f4ecfe86650319 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -28,6 +28,8 @@ Cfg::Cfg(GlobalContext *Ctx)
       IsInternalLinkage(false), HasError(false), ErrorMessage(""), Entry(NULL),
       NextInstNumber(1), Live(NULL),
       Target(TargetLowering::createLowering(Ctx->getTargetArch(), this)),
+      TargetAssembler(
+          TargetLowering::createAssembler(Ctx->getTargetArch(), this)),
       CurrentNode(NULL) {}
 
 Cfg::~Cfg() {}