[driver] add support for the combination of -c and -o
[driver] add support for the combination of -c and -o

This is unspecified behaviour[1], but it seems that almost everybody out
there relies on that, so.

[1] “-o outfile: Use the pathname outfile, instead of the default a.out,
for the executable file produced. If the -o option is present with -c or
-E, the result is unspecified.”

k0gaMSX/scc,k0gaMSX/scc,k0gaMSX/scc