Feature request

Currently value-of<BackedEnum> gives an error like PHPDoc tag @param for parameter $countryName contains unresolvable type., it would be nice to have support for this though.
Playground example: https://phpstan.org/r/8369e6e4-b6d7-4210-9a5d-92b754e0f2d7

Additionally PHPStan does not error on types that have this as array key: array<value-of<BackedEnum>, bool>, which means that it silently accepts incorrect code in this case (key-of has the same issue in this case, I guess that should just not be allowed though).
Playground example: https://phpstan.org/r/50d372e7-f7bf-49a2-8456-2eb89d97b7bc

Declaring array<value-of<BackedEnum>> does at least correctly warn about an unresolvable type, so that case is not silent.

Until a time that enums can be used as array keys it would be nice to support this to enforce correct code.
Let me now what you think about this use-case.

Did PHPStan help you today? Did it make you happy in any way?

Today I used enums together with match, and phpstan gives a nice error when a case is forgotten in match if there is no default defined, which is great!