re PR ada/29015 (Ada 2005 observer pattern with mutually dependent packages and containers produces compiler error)

    gcc/ada/
	PR ada/29015
	* sem_ch12.adb (Instantiate_Type): Check whether the full view of
	the type is known instead of the underlying type.

    gcc/testsuite/
	PR ada/29015
	* gnat.dg/incomplete1.ads, gnat.dg/incomplete2.ads,
	gnat.dg/incomplete2.adb: New.

From-SVN: r134345