cobol/119302 - transform gcobol.3 name during install, install as gcobol-io.3

The following installs gcobol.3 as gcobol-io.3 and applies
program-transform-name to the gcobol-io part.  This follows
naming of the pdf and the html variants.
It also uses $(man1ext) and $(man3ext) consistently.

	PR cobol/119302
gcc/cobol/
	* Make-lang.in (GCOBOLIO_INSTALL_NAME): Define.
	Use $(GCOBOLIO_INSTALL_NAME) for gcobol.3 manpage source
	upon install.
1 file changed