Improving debugging (gdb) support

[Eric Pouech]

> Does gdb really support 16-bit pointers now?  Otherwise I don't see
> how you can step through 16-bit code. And even if 16-bit binaries are
> not really important, support for 16-bit pointers definitely is.
I responded to fast. Of course, only the stepping thru wine's builtin
16 bit modules is available (but that's 32 bit code)
For pointer deref, one quick solution is to add one command to gdb which
converts a segmented pointer into a linear address. Then this linear 
address can be used in any gdb command (it'll much more harder to
add segmented pointers support though out every expression)

A+