[Bug c++/86183] Scoped enumeration instantiated even if not required

[zhonghao at pku dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86183

--- Comment #2 from zhonghao at pku dot org.cn ---
(In reply to Jonathan Wakely from comment #1)
> The definition of a member scoped enumaration type should not be
> instantiated by the implicit instantiation of the class template.

Is the code illegal? The latest clang++ still accepts the code. If the code is
illegal, I will report the problem to clang.