Fix ARMv6 Linux cross-build

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/bootstrap.h"
 #include "vm/compiler.h"
 #include "vm/constant_propagator.h"
@@ skipping 362 matching lines @@
 }
 
 
 intptr_t CheckClassInstr::ComputeCidMask() const {
   ASSERT(IsBitTest());
   intptr_t min = cids_.ComputeLowestCid();
   intptr_t mask = 0;
   for (intptr_t i = 0; i < cids_.length(); ++i) {
     intptr_t run;
     uintptr_t range = 1ul + cids_[i].Extent();
-    if (range >= kBitsPerWord) {
+    if (range >= static_cast<uintptr_t>(kBitsPerWord)) {
       run = -1;
     } else {
       run = (1 << range) - 1;
     }
     mask |= run << (cids_[i].cid_start - min);
   }
   return mask;
 }
 
 
@@ skipping 3933 matching lines @@
                      "native function '%s' (%" Pd " arguments) cannot be found",
                      native_name().ToCString(), function().NumParameters());
   }
   set_is_auto_scope(auto_setup_scope);
   set_native_c_function(native_function);
 }
 
 #undef __
 
 }  // namespace dart