I ran into some issues building nmstl on Linux-ppc,
this patch contains the fixes.

i386 only assembly
I 'borrowed' the ppc equivalents (see patch).

Non-declared eos() in iserial (nmstl/serial)
Recent versions of GCC refused to build this, so
I added virtual functions to make it happy.
If something is broken now, this caused it.  Sorry.

Treating getchar() as if it returned a char.
Now treats it correctly, using an int.
Casts the result to a char when being used.