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

src/IceGlobalInits.h

Index: src/IceGlobalInits.h
diff --git a/src/IceGlobalInits.h b/src/IceGlobalInits.h
index c6804de40a3d4486a84e3baf98e462a8bf12376e..c15aed00ec3e9bf94b091ef0069d286afac5f95b 100644
--- a/src/IceGlobalInits.h
+++ b/src/IceGlobalInits.h
@@ -172,7 +172,7 @@ public:
   };
 
   /// Models the data in a data initializer.
-  typedef std::vector<char> DataVecType;
+  using DataVecType = std::vector<char>;
 
   /// Defines a sequence of byte values as a data initializer.
   class DataInitializer : public Initializer {
@@ -269,7 +269,7 @@ public:
   };
 
   /// Models the list of initializers.
-  typedef std::vector<std::unique_ptr<Initializer>> InitializerListType;
+  using InitializerListType = std::vector<std::unique_ptr<Initializer>>;
 
   static VariableDeclaration *create(GlobalContext *Context) {
     return new (Context->allocate<VariableDeclaration>()) VariableDeclaration();