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

runtime/vm/megamorphic_cache_table.cc

 // Copyright (c) 2012, 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/megamorphic_cache_table.h"
 
 #include <stdlib.h>
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/stub_code.h"
@@ skipping 43 matching lines @@
   // The miss handler for a class ID not found in the table is invoked as a
   // normal Dart function.
   const Code& code =
       Code::Handle(StubCode::Generate("_stub_MegamorphicMiss",
                                       StubCode::GenerateMegamorphicMissStub));
   // When FLAG_lazy_dispatchers=false, this stub can be on the stack during
   // exceptions, but it has a corresponding function so IsStubCode is false and
   // it is considered in the search for an exception handler.
   code.set_exception_handlers(Object::empty_exception_handlers());
   const Class& cls =
-      Class::Handle(Type::Handle(Type::Function()).type_class());
+      Class::Handle(Type::Handle(Type::DartFunctionType()).type_class());
   const Function& function =
       Function::Handle(Function::New(Symbols::MegamorphicMiss(),
                                      RawFunction::kRegularFunction,
                                      false,  // Not static.
                                      false,  // Not const.
                                      false,  // Not abstract.
                                      false,  // Not external.
                                      false,  // Not native.
                                      cls,
                                      TokenPosition::kNoSource));
@@ skipping 18 matching lines @@
     cache ^= table.At(i);
     buckets = cache.buckets();
     size += MegamorphicCache::InstanceSize();
     size += Array::InstanceSize(buckets.Length());
   }
   OS::Print("%" Pd " megamorphic caches using %" Pd "KB.\n",
             table.Length(), size / 1024);
 }
 
 }  // namespace dart