monitor: implement x86 info tlb for PAE and long modes

'info tlb' didn't show correct information for PAE mode and
x86_64 long mode.

Implement the missing modes. Also print NX bit for PAE and long modes.
Fix off-by-one error in 32 bit mode mask.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
