[COMMIT] Enable gdb.dwarf2 tests on *-*-openbsd* and fix them

[M.M. Kettenis]

Daniel Jacobowitz <drow@false.org> wrote: 

> Thanks!  .... do you know why this difference happens?
> 
> > -gdb_test "list func_cu1" "4\tFile 1 Line 4"
> > +gdb_test "list func_cu1" "4\[ \t\]+File 1 Line 4"

I believe it depends whether the pty driver expands tabs or not.

Mark