re PR c++/45329 (When printing a list of candidate functions, explain why each...

re PR c++/45329 (When printing a list of candidate functions, explain why each function failed to match.)

gcc/cp/
	PR c++/45329
	* call.c (struct conversion): Document bad_p field.
	(enum rejection_reason_code): Define.
	(struct conversion_info): Define.
	(struct rejection_reason): Define.
	(struct z_candidate): Add `reason' field.
	(add_candidate): Add `reason' parameter.  Store it in CAND.
	(alloc_rejection, arity_rejection, arg_conversion_rejection):
	New functions.
	(bad_arg_conversion_rejection): New function.
	(convert_class_to_reference): Add comment.
	(remaining_arguments): New function.
	(add_function_candidate): Record rejection reason and pass it to
	add_candidate.
	(add_conv_candidate, build_builtin_candidate): Likewise.
	(add_template_candidate_real): Likewise.
	(print_conversion_rejection): New function.
	(print_z_candidate): Print CAND->REASON if it exists.  Adjust
	diagnostic strings.
	(print_z_candidates): Add location_t argument.  Adjust calling
	sequence for print_z_candidate. Print header line directly.
	(build_user_type_conversion_1): Add reason for rejection to
	CAND.  Adjust call to print_z_candidates.
	(print_error_for_call_failure): New function.
	(build_new_function_call): Call it.  Adjust call to
	print_z_candidates.
	(build_operator_new_call): Likewise.
	(build_op_call): Likewise.
	(build_conditional_expr): Likewise.
	(build_new_op): Likewise.
	(build_new_method_call): Likewise.

gcc/testsuite/
	PR c++/45329
	* testsuite/g++.dg/conversion/ambig1.C: Adjust.
	* testsuite/g++.dg/conversion/op1.C: Adjust.
	* testsuite/g++.dg/conversion/simd1.C: Adjust.
	* testsuite/g++.dg/cpp0x/defaulted14.C: Adjust.
	* testsuite/g++.dg/cpp0x/defaulted18.C: Adjust.
	* testsuite/g++.dg/cpp0x/defaulted20.C: Adjust.
	* testsuite/g++.dg/cpp0x/explicit3.C: Adjust.
	* testsuite/g++.dg/cpp0x/explicit4.C: Adjust.
	* testsuite/g++.dg/cpp0x/implicit4.C: Adjust.
	* testsuite/g++.dg/cpp0x/nullptr15.C: Adjust.
	* testsuite/g++.dg/cpp0x/nullptr19.C: Adjust.
	* testsuite/g++.dg/cpp0x/pr31431-2.C: Adjust.
	* testsuite/g++.dg/cpp0x/pr31431.C: Adjust.
	* testsuite/g++.dg/cpp0x/pr31434.C: Adjust.
	* testsuite/g++.dg/cpp0x/pr31437.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv2n.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv3n.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv4n.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv5n.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv6n.C: Adjust.
	* testsuite/g++.dg/cpp0x/rv7n.C: Adjust.
	* testsuite/g++.dg/cpp0x/temp_default2.C: Adjust.
	* testsuite/g++.dg/cpp0x/trailing4.C: Adjust.
	* testsuite/g++.dg/cpp0x/variadic-ex3.C: Adjust.
	* testsuite/g++.dg/cpp0x/variadic-ex4.C: Adjust.
	* testsuite/g++.dg/cpp0x/variadic35.C: Adjust.
	* testsuite/g++.dg/cpp0x/vt-35147.C: Adjust.
	* testsuite/g++.dg/cpp0x/vt-37737-2.C: Adjust.
	* testsuite/g++.dg/expr/cond9.C: Adjust.
	* testsuite/g++.dg/expr/pmf-1.C: Adjust.
	* testsuite/g++.dg/ext/label5.C: Adjust.
	* testsuite/g++.dg/ext/visibility/anon8.C: Adjust.
	* testsuite/g++.dg/ext/vla2.C: Adjust.
	* testsuite/g++.dg/gomp/pr26690-1.C: Adjust.
	* testsuite/g++.dg/gomp/pr26690-2.C: Adjust.
	* testsuite/g++.dg/init/synth2.C: Adjust.
	* testsuite/g++.dg/lookup/conv-1.C: Adjust.
	* testsuite/g++.dg/lookup/new1.C: Adjust.
	* testsuite/g++.dg/lookup/using9.C: Adjust.
	* testsuite/g++.dg/other/error13.C: Adjust.
	* testsuite/g++.dg/other/error20.C: Adjust.
	* testsuite/g++.dg/other/error31.C: Adjust.
	* testsuite/g++.dg/other/pr28114.C: Adjust.
	* testsuite/g++.dg/other/ptrmem10.C: Adjust.
	* testsuite/g++.dg/other/ptrmem11.C: Adjust.
	* testsuite/g++.dg/overload/ambig1.C: Adjust.
	* testsuite/g++.dg/overload/arg3.C: Adjust.
	* testsuite/g++.dg/overload/builtin1.C: Adjust.
	* testsuite/g++.dg/overload/copy1.C: Adjust.
	* testsuite/g++.dg/overload/new1.C: Adjust.
	* testsuite/g++.dg/overload/template4.C: Adjust.
	* testsuite/g++.dg/overload/unknown1.C: Adjust.
	* testsuite/g++.dg/overload/using2.C: Adjust.
	* testsuite/g++.dg/parse/crash5.C: Adjust.
	* testsuite/g++.dg/parse/error19.C: Adjust.
	* testsuite/g++.dg/parse/error28.C: Adjust.
	* testsuite/g++.dg/parse/template7.C: Adjust.
	* testsuite/g++.dg/parse/typename7.C: Adjust.
	* testsuite/g++.dg/rtti/typeid6.C: Adjust.
	* testsuite/g++.dg/tc1/dr152.C: Adjust.
	* testsuite/g++.dg/template/conv11.C: Adjust.
	* testsuite/g++.dg/template/copy1.C: Adjust.
	* testsuite/g++.dg/template/crash37.C: Adjust.
	* testsuite/g++.dg/template/deduce3.C: Adjust.
	* testsuite/g++.dg/template/dependent-expr5.C: Adjust.
	* testsuite/g++.dg/template/error38.C: Adjust.
	* testsuite/g++.dg/template/error40.C: Adjust.
	* testsuite/g++.dg/template/friend.C: Adjust.
	* testsuite/g++.dg/template/incomplete2.C: Adjust.
	* testsuite/g++.dg/template/instantiate5.C: Adjust.
	* testsuite/g++.dg/template/local4.C: Adjust.
	* testsuite/g++.dg/template/local6.C: Adjust.
	* testsuite/g++.dg/template/new3.C: Adjust.
	* testsuite/g++.dg/template/operator9.C: Adjust.
	* testsuite/g++.dg/template/overload6.C: Adjust.
	* testsuite/g++.dg/template/ptrmem2.C: Adjust.
	* testsuite/g++.dg/template/ptrmem20.C: Adjust.
	* testsuite/g++.dg/template/ptrmem4.C: Adjust.
	* testsuite/g++.dg/template/ptrmem8.C: Adjust.
	* testsuite/g++.dg/template/qualttp5.C: Adjust.
	* testsuite/g++.dg/template/sfinae2.C: Adjust.
	* testsuite/g++.dg/template/spec22.C: Adjust.
	* testsuite/g++.dg/template/spec23.C: Adjust.
	* testsuite/g++.dg/template/ttp25.C: Adjust.
	* testsuite/g++.dg/template/typedef4.C: Adjust.
	* testsuite/g++.dg/template/unify10.C: Adjust.
	* testsuite/g++.dg/template/unify11.C: Adjust.
	* testsuite/g++.dg/template/unify6.C: Adjust.
	* testsuite/g++.dg/template/unify7.C: Adjust.
	* testsuite/g++.dg/template/unify9.C: Adjust.
	* testsuite/g++.dg/template/varmod1.C: Adjust.
	* testsuite/g++.old-deja/g++.benjamin/15799.C: Adjust.
	* testsuite/g++.old-deja/g++.benjamin/15800-1.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/ambiguity1.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/crash29.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/crash48.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/crash56.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/cvt3.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/overload1.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/overload4.C: Adjust.
	* testsuite/g++.old-deja/g++.brendan/overload9.C: Adjust.
	* testsuite/g++.old-deja/g++.bugs/900127_01.C: Adjust.
	* testsuite/g++.old-deja/g++.bugs/900205_04.C: Adjust.
	* testsuite/g++.old-deja/g++.bugs/900330_02.C: Adjust.
	* testsuite/g++.old-deja/g++.bugs/900404_03.C: Adjust.
	* testsuite/g++.old-deja/g++.bugs/900514_03.C: Adjust.
	* testsuite/g++.old-deja/g++.eh/ctor1.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/conversion11.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/crash3.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/overload16.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/overload28.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/scoping10.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/template30.C: Adjust.
	* testsuite/g++.old-deja/g++.jason/temporary2.C: Adjust.
	* testsuite/g++.old-deja/g++.law/arg1.C: Adjust.
	* testsuite/g++.old-deja/g++.law/arg11.C: Adjust.
	* testsuite/g++.old-deja/g++.law/arm9.C: Adjust.
	* testsuite/g++.old-deja/g++.law/ctors11.C: Adjust.
	* testsuite/g++.old-deja/g++.law/ctors17.C: Adjust.
	* testsuite/g++.old-deja/g++.law/ctors5.C: Adjust.
	* testsuite/g++.old-deja/g++.law/ctors9.C: Adjust.
	* testsuite/g++.old-deja/g++.law/enum4.C: Adjust.
	* testsuite/g++.old-deja/g++.law/missed-error2.C: Adjust.
	* testsuite/g++.old-deja/g++.law/operators32.C: Adjust.
	* testsuite/g++.old-deja/g++.law/operators9.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/net2.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/net22.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p11110.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p1989.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p2431.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p438.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p807a.C: Adjust.
	* testsuite/g++.old-deja/g++.mike/p9068.C: Adjust.
	* testsuite/g++.old-deja/g++.niklas/t120.C: Adjust.
	* testsuite/g++.old-deja/g++.niklas/t121.C: Adjust.
	* testsuite/g++.old-deja/g++.niklas/t128.C: Adjust.
	* testsuite/g++.old-deja/g++.ns/overload2.C: Adjust.
	* testsuite/g++.old-deja/g++.ns/using12.C: Adjust.
	* testsuite/g++.old-deja/g++.other/crash24.C: Adjust.
	* testsuite/g++.old-deja/g++.other/expr1.C: Adjust.
	* testsuite/g++.old-deja/g++.other/overload11.C: Adjust.
	* testsuite/g++.old-deja/g++.other/pmf3.C: Adjust.
	* testsuite/g++.old-deja/g++.other/volatile1.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/auto_ptr.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/crash28.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/crash60.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/explicit38.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/explicit39.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/explicit41.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/explicit67.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/explicit77.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/expr2.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/ptrmem10.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/ptrmem6.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/spec35.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/spec5.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/spec6.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/t05.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/t24.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/unify4.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/unify6.C: Adjust.
	* testsuite/g++.old-deja/g++.pt/unify8.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb109.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb119.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb131.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb22.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb69.C: Adjust.
	* testsuite/g++.old-deja/g++.robertl/eb98.C: Adjust.

From-SVN: r167607