PR c++/57891
	* call.c (struct conversion): Add check_narrowing_const_only.
	(build_converted_constant_expr): Set check_narrowing and
	check_narrowing_const_only.  Give error if expr is error node.
	(convert_like_real): Pass it to check_narrowing.
	* cp-tree.h (check_narrowing): Add a default parameter.
	* decl.c (compute_array_index_type): Use input_location instead of
	location_of.
	* pt.c (convert_nontype_argument): Return NULL_TREE if tf_error.
	* typeck2.c (check_narrowing): Don't warn for instantiation-dependent
	expressions.  Call maybe_constant_value instead of
	fold_non_dependent_expr.  Don't mention { } in diagnostic.  Only check
	narrowing for constants if CONST_ONLY.

	* g++.dg/cpp0x/Wnarrowing6.C: New test.
	* g++.dg/cpp0x/Wnarrowing7.C: New test.
	* g++.dg/cpp0x/Wnarrowing8.C: New test.
	* g++.dg/cpp0x/Wnarrowing9.C: New test.
	* g++.dg/cpp0x/Wnarrowing10.C: New test.
	* g++.dg/cpp0x/constexpr-47969.C: Adjust dg-error.
	* g++.dg/cpp0x/constexpr-ex2.C: Likewise.
	* g++.dg/cpp0x/constexpr-targ.C: Likewise.
	* g++.dg/cpp0x/scoped_enum2.C: Likewise.
	* g++.dg/ext/stmtexpr15.C: Likewise.
	* g++.dg/gomp/pr47963.C: Likewise.
	* g++.dg/init/new37.C: Likewise.
	* g++.dg/init/new43.C: Likewise.
	* g++.dg/other/fold1.C: Likewise.
	* g++.dg/parse/array-size2.C: Likewise.
	* g++.dg/template/dependent-name3.C: Likewise.
	* g++.dg/cpp0x/constexpr-data2.C: Add dg-error.
	* g++.dg/other/vrp1.C: Likewise.
	* g++.dg/template/char1.C: Likewise.

From-SVN: r263523