Refactor the process of choosing validators.

src/trusted/validator_x86/nccopycode.h

 /*
- * Copyright (c) 2011 The Native Client Authors. All rights reserved.
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_NCCOPYCODE_H_
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_NCCOPYCODE_H_
 
-#include "native_client/src/trusted/validator/x86/types_memory_model.h"
-
-#if NACL_TARGET_SUBARCH == 32
-/* Copies code from src to dest in a thread safe way, returns 1 on success,
- * returns 0 on error. This will likely assert on error to avoid partially
- * copied code or undefined state.
+/* Copies a single instruction, avoiding the possibility of other threads
+ * executing a partially changed instruction.
  */
-int NCCopyCode(uint8_t *dst, uint8_t *src, NaClPcAddress vbase,
-                size_t sz, int bundle_size);
-
-#elif NACL_TARGET_SUBARCH == 64
-/* Copies code from src to dest in a thread safe way, returns 1 on success,
- * returns 0 on error. This will likely assert on error to avoid partially
- * copied code or undefined state.
- */
-int NaClCopyCodeIter(uint8_t *dst, uint8_t *src,
-                     NaClPcAddress vbase, size_t size);
-#else
-#error "Unknown Platform"
-#endif
+int NaClCopyInstructionX86(uint8_t *dst, uint8_t *src, uint8_t sz);
 
 #endif  /* NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_COPYCODE_H_ */