[Bug c++/103868] ICE at end of coroutine when using asio

["marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103868

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
Created attachment 52116
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52116&action=edit
Partially reduced test-case

The test-case fails with the following on master:

$ ./xgcc -B. /tmp/x.ii -c -std=c++20 -w
during RTL pass: expand
/tmp/x.ii: In function ‘void
malloy::test::client_ws_handler_coro(client_ws_handler_coro<false>(malloy::error_code,
std::shared_ptr<malloy::websocket::connection<true>
>)::_ZN6malloy4test22client_ws_handler_coroILb0EEEN5boost4asio9awaitableIvNS3_15any_io_executorEEENS2_6system10error_codeESt10shared_ptrINS_9websocket10connectionILb1EEEE.Frame*)’:
/tmp/x.ii:1035:70: internal compiler error: in make_decl_rtl, at varasm.c:1446
 1035 |   auto size = co_await conn->read(*buffer, boost::asio::use_awaitable);
      |                                                                      ^
0x8f7d91 make_decl_rtl(tree_node*)
        /home/marxin/Programming/gcc/gcc/varasm.c:1446
0xe7ede7 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        /home/marxin/Programming/gcc/gcc/expr.c:10550
0xe87d77 expand_expr
        /home/marxin/Programming/gcc/gcc/expr.h:301
0xe87d77 expand_expr_addr_expr_1
        /home/marxin/Programming/gcc/gcc/expr.c:8427
0xe7e2c4 expand_expr_addr_expr
        /home/marxin/Programming/gcc/gcc/expr.c:8548
0xe7e2c4 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        /home/marxin/Programming/gcc/gcc/expr.c:11764
0xe8aa46 store_expr(tree_node*, rtx_def*, int, bool, bool)
        /home/marxin/Programming/gcc/gcc/expr.c:6087
0xe8c25d expand_assignment(tree_node*, tree_node*, bool)
        /home/marxin/Programming/gcc/gcc/expr.c:5819
0xd4b07a expand_gimple_stmt_1
        /home/marxin/Programming/gcc/gcc/cfgexpand.c:3930
0xd4b07a expand_gimple_stmt
        /home/marxin/Programming/gcc/gcc/cfgexpand.c:4028
0xd5155c expand_gimple_basic_block
        /home/marxin/Programming/gcc/gcc/cfgexpand.c:6069
0xd53727 execute
        /home/marxin/Programming/gcc/gcc/cfgexpand.c:6795
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

Note it uses coroutines and -fconcepts.

$ (gdb) p debug_tree(decl)
 <var_decl 0x7ffff7434d80 _Coro_promise
    type <record_type 0x7ffff7462bd0 promise_type sizes-gimplified cxx-odr-p
type_5 type_6 QI
        size <integer_cst 0x7ffff75f3048 constant 8>
        unit-size <integer_cst 0x7ffff75f3060 constant 1>
        align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff7462b28
        fields <function_decl 0x7ffff7140000 __dt  type <method_type
0x7ffff713b2a0>
            public abstract external autoinline decl_3 decl_8 QI
/tmp/x.ii:982:7 align:16 warn_if_not_align:0 context <record_type
0x7ffff7462b28 awaitable_frame>
            full-name "constexpr boost::asio::detail::awaitable_frame<void,
boost::asio::any_io_executor>::~awaitable_frame() noexcept (<uninstantiated>)"
            not-really-extern chain <function_decl 0x7ffff7140200 __dt_base >>
context <namespace_decl 0x7ffff7338e40 detail>
        full-name "std::__n4861::coroutine_traits<boost::asio::awaitable<void>,
boost::system::error_code, std::shared_ptr<malloy::websocket::connection<true>
> >::promise_type"
        X() X(constX&) this=(X&) n_parents=1 use_template=1 interface-unknown
        pointer_to_this <pointer_type 0x7ffff7469498> chain <type_decl
0x7ffff7450d10 awaitable_frame>>
    addressable used read QI /tmp/x.ii:1035:70 size <integer_cst 0x7ffff75f3048
8> unit-size <integer_cst 0x7ffff75f3060 1>
    align:8 warn_if_not_align:0>
$1 = void