Add tzcnt as an acceptable instruction to the x86-32 validator (it already

src/trusted/validator/x86/ncval_seg_sfi/gen/ncdecodetab_64.h

 /* native_client/src/trusted/validator/x86/ncval_seg_sfi/gen/ncdecodetab_64.h
  * THIS FILE IS AUTO-GENERATED. DO NOT EDIT.
  * Compiled for x86-64 bit mode.
  *
  * You must include ncdecode.h before this file.
  */
 
 static const struct OpInfo kNopInst = { NACLi_NOP, 0, 1, 0 };
 
 static const NCNopTrieNode kNcNopTrieNode[] = {
@@ skipping 1515 matching lines @@
   /* b2 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b3 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b4 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b5 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b6 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b7 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* b8 */  { NACLi_POPCNT, 1, 1, 0 },  /* popcnt */
   /* b9 */  { NACLi_INVALID, 0, 1, 0 }, /* reserved */
   /* ba */  { NACLi_INVALID, 0, 2, 0 }, /* reserved */
   /* bb */  { NACLi_INVALID, 0, 1, 0 }, /* reserved */
-  /* bc */  { NACLi_INVALID, 0, 1, 0 }, /* reserved */
-  /* bd */  { NACLi_LZCNT, 1, 1, 0 },   /* lzcnt $Gv, $Ev */
+  /* bc */  { NACLi_386, 1, 1, 0 },     /* tzcnt $Gv, $Ev */
+  /* bd */  { NACLi_386, 1, 1, 0 },     /* lzcnt $Gv, $Ev */
   /* be */  { NACLi_INVALID, 1, 1, 0 }, /* reserved */
   /* bf */  { NACLi_INVALID, 0, 1, 0 }, /* reserved */
   /* c0 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* c1 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
   /* c2 */  { NACLi_SSE, 1, 2, 0 },     /* cmpss $V, $W, $I */
   /* c3 */  { NACLi_INVALID, 0, 1, 0 }, /* invalid */
   /* c4 */  { NACLi_INVALID, 0, 1, 0 }, /* invalid */
   /* c5 */  { NACLi_INVALID, 0, 1, 0 }, /* invalid */
   /* c6 */  { NACLi_INVALID, 0, 1, 0 }, /* invalid */
   /* c7 */  { NACLi_UNDEFINED, 0, 1, 0 },       /* undefined */
@@ skipping 4454 matching lines @@
     /* 01 */ DECODE_OPS_DEFAULT_32,
     /* 02 */ DECODE_OPS_DEFAULT_32,
     /* 03 */ DECODE_OPS_DEFAULT_32,
     /* 04 */ DECODE_OPS_DEFAULT_32,
     /* 05 */ DECODE_OPS_DEFAULT_32,
     /* 06 */ DECODE_OPS_DEFAULT_32,
     /* 07 */ DECODE_OPS_DEFAULT_32,
   },
 };