Remove recently introduced FunctionType vm class by merging it into class Type.

runtime/vm/exceptions.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/exceptions.h"
 
 #include "platform/address_sanitizer.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 475 matching lines @@
       pieces.Add(Symbols::SingleQuote());
       if (exception_type == kCast) {
         pieces.Add(dst_name);
       } else if (dst_name.Length() > 0) {
         pieces.Add(Symbols::SpaceOfSpace());
         pieces.Add(Symbols::SingleQuote());
         pieces.Add(dst_name);
         pieces.Add(Symbols::SingleQuote());
       }
       // Print URIs of src and dst types.
-      pieces.Add(Symbols::SpaceWhereNewLine());
+      // Do not print "where" when no URIs get printed.
+      bool printed_where = false;
       if (!src_type.IsNull()) {
-        pieces.Add(String::Handle(zone, src_type.EnumerateURIs()));
+        const String& uris = String::Handle(zone, src_type.EnumerateURIs());
+        if (uris.Length() > Symbols::SpaceIsFromSpace().Length()) {
+          printed_where = true;
+          pieces.Add(Symbols::SpaceWhereNewLine());
+          pieces.Add(uris);
+        }
       }
       if (!dst_type.IsDynamicType() && !dst_type.IsVoidType()) {
-        pieces.Add(String::Handle(zone, dst_type.EnumerateURIs()));
+        const String& uris = String::Handle(zone, dst_type.EnumerateURIs());
+        if (uris.Length() > Symbols::SpaceIsFromSpace().Length()) {
+          if (!printed_where) {
+            pieces.Add(Symbols::SpaceWhereNewLine());
+          }
+          pieces.Add(uris);
+        }
       }
     }
   }
   const String& error_msg =
       String::Handle(zone, Symbols::FromConcatAll(pieces));
   args.SetAt(3, error_msg);
 
   // Type errors in the core library may be difficult to diagnose.
   // Print type error information before throwing the error when debugging.
   if (FLAG_print_stacktrace_at_throw) {
@@ skipping 187 matching lines @@
   }
 
   return DartLibraryCalls::InstanceCreate(library,
                                           *class_name,
                                           *constructor_name,
                                           arguments);
 }
 
 
 }  // namespace dart