Gentle start with removing explicit interfaces

runtime/vm/intrinsifier_ia32.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.
 //
 // The intrinsic code below is executed before a method has built its frame.
 // The return address is on the stack and the arguments below it.
 // Registers EDX (arguments descriptor) and ECX (function) must be preserved.
 // Each intrinsification method returns true if the corresponding
 // Dart method was intrinsified.
 
@@ skipping 194 matching lines @@
     __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
     // Get type at index 0.
     __ movl(EAX, FieldAddress(EBX, TypeArguments::type_at_offset(0)));
     __ CompareObject(EAX, Type::ZoneHandle(Type::DynamicType()));
     __ j(EQUAL,  &checked_ok, Assembler::kNearJump);
     // Check for int and num.
     __ testl(EDI, Immediate(kSmiTagMask));  // Value is Smi?
     __ j(NOT_ZERO, &fall_through, Assembler::kNearJump);  // Non-smi value.
     __ CompareObject(EAX, Type::ZoneHandle(Type::IntInterface()));
     __ j(EQUAL,  &checked_ok, Assembler::kNearJump);
-    __ CompareObject(EAX, Type::ZoneHandle(Type::NumberInterface()));
+    __ CompareObject(EAX, Type::ZoneHandle(Type::Number()));
     __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
     __ Bind(&checked_ok);
   }
   __ movl(EBX, Address(ESP, + 2 * kWordSize));  // Index.
   __ testl(EBX, Immediate(kSmiTagMask));
   // Index not Smi.
   __ j(NOT_ZERO, &fall_through, Assembler::kNearJump);
   __ movl(EAX, Address(ESP, + 3 * kWordSize));  // Array.
   // Range check.
   __ cmpl(EBX, FieldAddress(EAX, Array::length_offset()));
@@ skipping 1138 matching lines @@
   __ Bind(&is_true);
   __ LoadObject(EAX, bool_true);
   __ ret();
   return true;
 }
 
 #undef __
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32