c++: printing AGGR_INIT_EXPR args

c++: printing AGGR_INIT_EXPR args

PR30854 was about wrongly dumping the dummy object argument to a
constructor; r126582 in 4.3 fixed that by skipping the first argument.  But
not all functions called by AGGR_INIT_EXPR are constructors, as observed in
PR116634; we shouldn't skip for non-member functions.  And let's combine the
printing code for CALL_EXPR and AGGR_INIT_EXPR.

This doesn't make us accept the ill-formed 116634 testcase again with a
pedwarn, just fixes the diagnostic issue.

	PR c++/30854
	PR c++/116634

gcc/cp/ChangeLog:

	* error.cc (dump_aggr_init_expr_args): Remove.
	(dump_call_expr_args): Handle AGGR_INIT_EXPR.
	(dump_expr): Combine AGGR_INIT_EXPR and CALL_EXPR cases.

gcc/testsuite/ChangeLog:

	* g++.dg/coroutines/coro-bad-alloc-02-no-op-new-nt.C: Adjust
	diagnostic.
	* g++.dg/diagnostic/aggr-init1.C: New test.