Just add -x debugbreak-gdb.py to your usual GDB invocation or add source debugbreak-gdb.py to your $HOME/.gdbinit.
Here's a sample session:
$ cd debugbreak
$ make
$ gdb -q -x debugbreak-gdb.py test/break
Reading symbols from test/break...done.
(gdb) set disassemble-next-line 1
(gdb) run
Starting program: /home/fedora/debugbreak/test/break
Program received signal SIGTRAP, Trace/breakpoint trap.
main () at test/break.c:6
6 debug_break();
Program received signal SIGTRAP, Trace/breakpoint trap.
main () at test/break.c:6
6 debug_break();
(gdb) debugbreak-step
7 printf("hello world\n");
(gdb) debugbreak-continue
hello world
[Inferior 1 (process 12533) exited normally]
(gdb)
On ARM and POWER, trying to use step or stepi in place of debugbreak-step in the sesion above wouldn't have worked as execution would be stock on the breakpoint instruction.