Although the std::any constructors use decay_t to determine the type of
the contained value, std::any_cast should use the un-decayed type (and
so always fail for function and array types that decay to pointers).
Using remove_cv_t is correct, because the condition for std::any_cast
to return non-null is operand.type() == typeid(T) and typeid ignores
top-level cv-qualifiers.
PR libstdc++/90220
* include/std/any (__any_caster): Use remove_cv_t instead of decay_t.
Avoid a runtime check for types that can never be stored in std::any.
* testsuite/20_util/any/misc/any_cast.cc: Test std::any_cast with
array types.
From-SVN: r270547