i#842: Fix 64-bit inc/dec encoding.

Reviewer: bruening@google.com
i#842: Fix 64-bit inc/dec encoding.

Fixes issue 842.

Fix 64-bit inc/dec encoding.

Not sure if this is an elegant way to fix the issue, since opcodes 40+ in 64-bit
mode are 'N.E.' instead of 'Invalid' in Intel's manual.

[bruening, 2012-07-13 18:49:08]

LGTM

http://codereview.appspot.com/6353100/diff/1/trunk/core/x86/decode_table.c
File trunk/core/x86/decode_table.c (right):

http://codereview.appspot.com/6353100/diff/1/trunk/core/x86/decode_table.c#ne...
trunk/core/x86/decode_table.c:4326: {OP_inc,  0x400000, "inc", zAX, xx, zAX, xx,
xx, i64, (fW6&(~fWC)), t64e[1][0]},
using i64 when only this encoding is invalid seems fine (this is re: your N.E.
vs Invalid question) as this is an entry just for this encoding and on decode it
will not be examined.

for efficiency, it would be nice to not have to walk 8 invalid templates every
single time.  if 64-bit mode were static it would be an easy fix.  since it's
dynamic it would require extra code and it doesn't seem like something
worthwhile is feasible.