Remove signature classes from the VM.

runtime/vm/intrinsifier_mips.cc

 // Copyright (c) 2013, 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/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 1628 matching lines @@
   __ LoadObject(V0, Bool::True());
   __ Ret();
 }
 
 
 // Return type quickly for simple types (not parameterized and not signature).
 void Intrinsifier::ObjectRuntimeType(Assembler* assembler) {
   Label fall_through;
   __ lw(T0, Address(SP, 0 * kWordSize));
   __ LoadClassIdMayBeSmi(T1, T0);
+  __ BranchEqual(T1, Immediate(kClosureCid), &fall_through);
   __ LoadClassById(T2, T1);
   // T2: class of instance (T0).
 
-  __ lw(T1, FieldAddress(T2, Class::signature_function_offset()));
-  __ BranchNotEqual(T1, Object::null_object(), &fall_through);
-
   __ lhu(T1, FieldAddress(T2, Class::num_type_arguments_offset()));
   __ BranchNotEqual(T1, Immediate(0), &fall_through);
 
   __ lw(V0, FieldAddress(T2, Class::canonical_types_offset()));
   __ BranchEqual(V0, Object::null_object(), &fall_through);
   __ Ret();
 
   __ Bind(&fall_through);
 }
 
@@ skipping 567 matching lines @@
 
 void Intrinsifier::Profiler_getCurrentTag(Assembler* assembler) {
   __ LoadIsolate(V0);
   __ Ret();
   __ delay_slot()->lw(V0, Address(V0, Isolate::current_tag_offset()));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS