Eliminate the type distinction between BindInstr and DoInstr.

runtime/vm/intermediate_language_test.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/intermediate_language.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 TEST_CASE(InstructionTests) {
   TargetEntryInstr* target_instr = new TargetEntryInstr();
   EXPECT(target_instr->IsBlockEntry());
-  EXPECT(!target_instr->IsDo());
   EXPECT(!target_instr->IsBind());
-  DoInstr* do_instr = new DoInstr(new CurrentContextComp());
-  EXPECT(do_instr->IsDo());
-  EXPECT(!do_instr->IsBlockEntry());
-  EXPECT(!do_instr->IsBind());
+  BindInstr* bind_instr =
+      new BindInstr(BindInstr::kUnused, new CurrentContextComp());
+  EXPECT(bind_instr->IsBind());
+  EXPECT(!bind_instr->IsBlockEntry());
 }
 
 }  // namespace dart