[Bug c++/85210] ICE with broken structured binding in template

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85210

--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Confirmed.

On gcc-7-branch, with checking enabled, this is:

test.cc:5:8: internal compiler error: tree check: expected var_decl, have
parm_decl in cp_finish_decomp, at cp/decl.c:7354

7454          SET_DECL_DECOMPOSITION_P (d);

(gdb) p d
$1 = <parm_decl 0x7ffff1a1d280 j>

Started with r242408 ("Various C++17 decomposition fixes")

On trunk, this is:

internal compiler error: in fit_decomposition_lang_decl, at cp/lex.c:724

which started with r248748.