Link object files when passed in instead of source files

[hdamron17]

I know this is silly, but if we receive object files instead of source files we should link them immediately (still using cc) instead of complaining that they are not UTF-8. This will make working with CMake and Make much easier because they expect the compiler to handle the full compilation pipeline and allow separating into multiple stages.

Example

$ swcc -o sample.o -c sample.c
$ swcc -o sample sample.o
// second command currently tries to parse sample.o as source code and gives 'invalid UTF-8 error'
// should link sample.o into the sample executable