[Bug c++/63362] The c++11 triviality-traits need front-end help

["ville.voutilainen at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63362

--- Comment #10 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Reduced:

template <bool b> 
struct bool_
{
};

template <typename T, class... Args>
struct mytrait : bool_<__is_trivially_constructible(T, Args...)>
{
}

trivial_trait2.cpp:7:64: internal compiler error: tree check: expected class
âtypeâ, have âexceptionalâ (tree_list) in strip_typedefs, at cp/tree.c:1204
 struct mytrait : bool_<__is_trivially_constructible(T, Args...)>
                                                                ^
0xe02687 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
    ../../gcc/tree.c:9226
0x735d28 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
    ../../gcc/tree.h:2856
0x735d28 strip_typedefs(tree_node*)
    ../../gcc/cp/tree.c:1204
0x734c40 strip_typedefs_expr(tree_node*)
    ../../gcc/cp/tree.c:1396
0x5fe7d7 convert_template_argument
    ../../gcc/cp/pt.c:6658
0x5e125b coerce_template_parms
    ../../gcc/cp/pt.c:7080
0x5e92de lookup_template_class_1
    ../../gcc/cp/pt.c:7661
0x5e92de lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
    ../../gcc/cp/pt.c:7979
0x6ffd62 finish_template_type(tree_node*, tree_node*, int)
    ../../gcc/cp/semantics.c:2981
0x692bf9 cp_parser_template_id
    ../../gcc/cp/parser.c:13664
0x692f08 cp_parser_class_name
    ../../gcc/cp/parser.c:19491
0x68707a cp_parser_qualifying_entity
    ../../gcc/cp/parser.c:5571
0x68707a cp_parser_nested_name_specifier_opt
    ../../gcc/cp/parser.c:5296
0x67a1bb cp_parser_base_specifier
    ../../gcc/cp/parser.c:21239
0x67a1bb cp_parser_base_clause
    ../../gcc/cp/parser.c:21088
0x67a1bb cp_parser_class_head
    ../../gcc/cp/parser.c:20297
0x67a1bb cp_parser_class_specifier_1
    ../../gcc/cp/parser.c:19571
0x67b0c0 cp_parser_class_specifier
    ../../gcc/cp/parser.c:19863
0x67b0c0 cp_parser_type_specifier
    ../../gcc/cp/parser.c:14539
0x6961c1 cp_parser_decl_specifier_seq
    ../../gcc/cp/parser.c:11780
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