resourceloader: Don't add superfluous line breaks and semicolons

The logic was there but didn't work in practice because, just
like this code does itself, code doesn't usually end in ';'.
Instead it ends in ";\n" (trailing line break at end of file),
or even two line breaks (in case of concatenated scripts where
ResourceLoaderFileModule adds another line break).

This saves off a few bytes that were uselessly added in the
load.php output, like:

	...
	}( jQuery ) );

	;
	/**
	...

After this:

	}( jQuery ) );

	/**

The logic to add ;\n is still there, but the logic to not add it
when there already wasn't working (added in I3e8227ddb).

Change-Id: Ie055b37b3419ac6dca6349daf745bc48850fff3e
Merge "resourceloader: Don't add superfluous line breaks and semicolons"