call.c (standard_conversion): Reject pointer to member conversions from ambiguous, inaccessible or virtual bases.

cp:
	* call.c (standard_conversion): Reject pointer to member
	conversions from ambiguous, inaccessible or virtual bases.
	* typeck.c (build_static_cast): Don't check pointers to members
	specially.
testsuite:
	* g++.old-deja/g++.other/cast6.C: New test.

From-SVN: r37914