Refactor all instances of `typedef y x` to the C++11 `using x = y` syntax.

src/IceIntrinsics.h

 //===- subzero/src/IceIntrinsics.h - List of Ice Intrinsics -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 147 matching lines @@
   /// the function name does not have the common "llvm." prefix, nullptr is
   /// returned and Error is set to false.  Otherwise, tries to find a reference
   /// to a FullIntrinsicInfo entry (valid for the lifetime of the map).  If
   /// found, sets Error to false and returns the reference.  If not found, sets
   /// Error to true and returns nullptr (indicating an unknown "llvm.foo"
   /// intrinsic).
   const FullIntrinsicInfo *find(const IceString &Name, bool &Error) const;
 
 private:
   // TODO(jvoung): May want to switch to something like LLVM's StringMap.
-  typedef std::map<IceString, FullIntrinsicInfo> IntrinsicMap;
+  using IntrinsicMap = std::map<IceString, FullIntrinsicInfo>;
   IntrinsicMap Map;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINTRINSICS_H