Changeset b7e3949 in rtems for c/src/lib/libbsp/i386

Patch from Eric Valette <valette@…>. Most of this was included
in a previous patch. Comments from Eric:

patch_com2 was before your own fixes of raw IDT vector management
routine.
It mainly use human readable constants for the serial line driver code
+ the patch you gave me for com2 write routine.

I applied your patch for raw IDT mngt on top of that. Then made minor
cleaning in patch_idt_mngt. I hope this helps.