Add support to load/store byte fields.

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2811 matching lines @@
           : new(zone) Range();
       result->Shl(c->Integer32Value());
       return result;
     }
   }
   return HValue::InferRange(zone);
 }
 
 
 Range* HLoadNamedField::InferRange(Zone* zone) {
+  if (access().representation().IsByte()) {
+    return new(zone) Range(0, 255);
+  }
   if (access().IsStringLength()) {
     return new(zone) Range(0, String::kMaxLength);
   }
   return HValue::InferRange(zone);
 }
 
 
 Range* HLoadKeyed::InferRange(Zone* zone) {
   switch (elements_kind()) {
     case EXTERNAL_PIXEL_ELEMENTS:
@@ skipping 1426 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal