[Bug libstdc++/91259] Parenthesize requires clauses that contain expressions that are not just a value of type bool

[Casey at Carter dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91259

Casey Carter <Casey at Carter dot net> changed:

           What    |Removed                     |Added
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                 CC|                            |Casey at Carter dot net

--- Comment #2 from Casey Carter <Casey at Carter dot net> ---
It would be nice to fix this on gcc-9-branch as well so clang w/concepts can
use libstdc++.