Add initial integrated assembler w/ some Xmm ops.

src/IceDefs.h

Index: src/IceDefs.h
diff --git a/src/IceDefs.h b/src/IceDefs.h
index 44a61323ad769b684fbd2074693b18d4320abab0..90c6579a4fec688a4a6edd31d48c006d4d7e96d2 100644
--- a/src/IceDefs.h
+++ b/src/IceDefs.h
@@ -129,11 +129,6 @@ private:
   Timer &operator=(const Timer &) LLVM_DELETED_FUNCTION;
 };
 
-template <typename T> bool WouldOverflowAdd(T X, T Y) {
-  return ((X > 0 && Y > 0 && (X > std::numeric_limits<T>::max() - Y)) ||
-          (X < 0 && Y < 0 && (X < std::numeric_limits<T>::min() - Y)));
-}
-
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H