* ada/acats/run_acats: Treat 'gnatchop' the same way
	as 'gnatmake'.  Export GCC_DRIVER.
	* ada/acats/run_all.sh: Add target_gnatchop.  Use
	'host_gnatchop' and 'target_gnatchop' instead of 'gnatshop'.

From-SVN: r75551