additional cfinish command (patches for gdb command file)

finish leave the current active stack element, which cannot be used for programs or sections as those aren't (necessary) one C function.

I'd suggest to add a new command to work around this. Here are some hints for the necessary code:

cfinish-program: until exit_program; finish; finish cfinish-function: until exit_function; finish; finish cfinish-module: the two above but conditionaö cfinish-perform-out-of-line: until *frame_ptr->return_address_ptr cfinish-perform-inline: currently has to check for loop exit (EXIT PERFORM also jumps there - in this case generates an "implicit EXIT label") and use until there, I'm looking at inserting something similar like the frame_ptr to ease this. Using until should also "catch" GOBACK / EXIT PROGRAM|FUNCTION as those are on a different statck trace cfinish-perform-continue: similar like cfinish-perform-inline, until just before the end of the loop (EXIT PERFORM CYCLE also jumps there - in this case generates an "implicit EXIT label".