Rename is_call to always_calls and contains_call to can_call.

runtime/vm/locations.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/locations.h"
 
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph_compiler.h"
 
@@ skipping 94 matching lines @@
       temp(i).PrintTo(f);
     }
     f->Print("]");
   }
 
   if (!out().IsInvalid()) {
     f->Print(" => ");
     out().PrintTo(f);
   }
 
-  if (is_call()) f->Print(" C");
+  if (always_calls()) f->Print(" C");
 }
 
 }  // namespace dart