[php-src] Issue #7729: enums

Issue: https://github.com/php/php-src/issues/7729 Author: richirm77 ### Description Hello! There seems to be no way to get the string representation of an instance of an enum, except with var_export(). ```php enum Foo: string { case Bar = 'bar'; case Baz = 'baz'; } $bar = Foo::Bar; $bar_string = var_export($bar, true); ``` Also, what if I want to find out the backing value of an enum variable? ```php $backing_value = (new \ReflectionEnumBackedCase($bar, ???))->getBackingValue(); ``` Any ideas?