cp:	* pt.c (instantiate_class_template): Set location before
	substuting bases.
testsuite:
	* g++.dg/template/error2.C: New test.
	* g++.dg/lookup/using7.C: Adjust errors
	* g++.old-deja/g++.pt/crash36.C: Likewise.
	* g++.old-deja/g++.pt/derived3.C: Likewise.

From-SVN: r70476