re PR c++/11596 (ICE with int templates)

re PR c++/11596 (ICE with int templates)

cp:
	PR c++/11596
	* pt.c (maybe_fold_nontype_arg, maybe_fold_nontype_args): Remove.
	(tsubst_template_arg): New.
	(tsubst_template_arg_vector): Rename to ...
	(tsubst_template_args): ... this. Accept a TREE_LIST form. Use
	tsubst_template_arg.
	(coerce_template_parms): Use tsubst_template_arg for default
	value.
	(tsubst_template_parms): Likewise.
	(tsubst_aggr_type): Adjust.
	(tsubst_decl): Likewise.
	(tsubst): Use tsubst_template_arg for a DOMAIN. Adjust.
	(tsubst_copy) <TEMPLATE_ID_EXPR case>: Use tsubst_template_args.
testsuite:
	PR 11596
	* g++.dg/template/defarg3.C: New test.

	* g++.dg/ext/packed2.C: Pack member struct too. Explain why.

From-SVN: r69776