Doxygenize the documentation comments

src/IceTypes.cpp

 //===- subzero/src/IceTypes.cpp - Primitive type properties ---------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This file defines a few attributes of Subzero primitive types.
-//
+///
+/// \file
+/// This file defines a few attributes of Subzero primitive types.
+///
 //===----------------------------------------------------------------------===//
 
 #include "IceTypes.h"
 
 #include "IceDefs.h"
 
 namespace Ice {
 
 namespace {
 
@@ skipping 248 matching lines @@
       IsFirst = false;
     } else {
       Stream << ", ";
     }
     Stream << ArgTy;
   }
   Stream << ")";
 }
 
 } // end of namespace Ice