[Bug c/64509] _Generic throws error in unselected generic association

[maurits.de.jong at ericsson dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64509

--- Comment #2 from Martien de Jong <maurits.de.jong at ericsson dot com> ---
That's just rephrasing my bugreport. The question is, should it type check
while parsing an expression that may not be realized? The entire idea of
switching on a type is to prevent and fix type errors, no?