When debugging in gdb you might want to inspect instructions in mapped
pages or in exception vectors like 0x800 etc. This was previously not
possible in qemu since the *get_phys_page_debug() routine only looked
into the data tlb.
Change to fall back to look into instruction tlb and plain physical
pages.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stafford Horne <shorne@gmail.com>