Add tzcnt as an acceptable instruction to x86-64 validator (it already

src/trusted/validator/x86/decoder/gen/ncopcode_insts.h

 /* native_client/src/trusted/validator/x86/decoder/gen/ncopcode_insts.h
  * THIS FILE IS AUTO_GENERATED DO NOT EDIT.
  *
  * This file was auto-generated by enum_gen.py
  * from file ncopcode_insts.enum
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_DECODER_GEN_NCOPCODE_INSTS_H__
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_DECODER_GEN_NCOPCODE_INSTS_H__
 
@@ skipping 590 matching lines @@
   InstSubpd = 586,
   InstSubps = 587,
   InstSubsd = 588,
   InstSubss = 589,
   InstSwapgs = 590,
   InstSyscall = 591,
   InstSysenter = 592,
   InstSysexit = 593,
   InstSysret = 594,
   InstTest = 595,
-  InstUcomisd = 596,
-  InstUcomiss = 597,
-  InstUd2 = 598,
-  InstUnpckhpd = 599,
-  InstUnpckhps = 600,
-  InstUnpcklpd = 601,
-  InstUnpcklps = 602,
-  InstVerr = 603,
-  InstVerw = 604,
-  InstVmload = 605,
-  InstVmmcall = 606,
-  InstVmrun = 607,
-  InstVmsave = 608,
-  InstWbinvd = 609,
-  InstWrmsr = 610,
-  InstXadd = 611,
-  InstXchg = 612,
-  InstXlat = 613,
-  InstXor = 614,
-  InstXorpd = 615,
-  InstXorps = 616,
-  NaClMnemonicEnumSize = 617, /* special size marker */
+  InstTzcnt = 596,
+  InstUcomisd = 597,
+  InstUcomiss = 598,
+  InstUd2 = 599,
+  InstUnpckhpd = 600,
+  InstUnpckhps = 601,
+  InstUnpcklpd = 602,
+  InstUnpcklps = 603,
+  InstVerr = 604,
+  InstVerw = 605,
+  InstVmload = 606,
+  InstVmmcall = 607,
+  InstVmrun = 608,
+  InstVmsave = 609,
+  InstWbinvd = 610,
+  InstWrmsr = 611,
+  InstXadd = 612,
+  InstXchg = 613,
+  InstXlat = 614,
+  InstXor = 615,
+  InstXorpd = 616,
+  InstXorps = 617,
+  NaClMnemonicEnumSize = 618, /* special size marker */
 } NaClMnemonic;
 
 /* Returns the name of an NaClMnemonic constant. */
 extern const char* NaClMnemonicName(NaClMnemonic name);
 
 EXTERN_C_END
 
 #endif /* NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_DECODER_GEN_NCOPCODE_INSTS_H__ */