[Bug c++/65575] [c++-concepts] Parse error for requires clause on functions that return a reference type

[andrew.n.sutton at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65575

--- Comment #1 from Andrew Sutton <andrew.n.sutton at gmail dot com> ---
Confirmed and resolved in r221695. 

Removed the check for trailing requires-clauses on non-function declarators.
This should make the presence of a trailing-requires clause in a context where
it doesn't belong a syntax error (expected 'XXX', but got 'requires', for
example).