[committed] Fix comp-goto-1.c on 16 bit targets

[committed] Fix comp-goto-1.c on 16 bit targets

I don't remember what port triggered this, but it's obviously that
comp-goto-1.c needs to be fixed.

Basically the test has two implementations.  One is just a dummy with no return
value on main() triggering the new errors.

gcc/testsuite
	* gcc.c-torture/execute/comp-goto-1.c: Fix return value of main for
	16 bit targets.