PHP 8.0 language support tracking issue

[jakubmisek]

Configuration:

• [x] <LangVersion> allows to set 8.0, latest refers to 8.0, default 7.4

Language features:

• [x] Union types
  • [x] syntax, mixed
  • [x] type analysis, "null", nullability
  • [ ] runtime type check
• [x] Attributes
  • [x] new syntax
  • [x] resolve CLR attributes as before
  • [x] store metadata
  • [x] PHP reflection
• [x] Constructor properties (https://github.com/peachpiecompiler/peachpie/commit/0ea8da8d3ebf13dd920019c815103ea2f0c58033, https://github.com/peachpiecompiler/peachpie/commit/c8f10e81933bcba819f3f4310d9b306485d4e064)
• [x] static return type
• [x] match expression (https://wiki.php.net/rfc/match_expression_v2)
• [ ] Nullsafe operator with short-circuit evaluation (https://wiki.php.net/rfc/nullsafe_operator)
• [ ] Named arguments (https://wiki.php.net/rfc/named_params)
  • [ ] call_user_func*() and internal PhpRoutine.Invoke(Context, PhpArray) to support named arguments
  • [ ] use in ReflectionAttribute::newInstance() accordingly
  • [ ] Variadic functions and argument unpacking
  • [ ] error when calling a virtual method that changes the parameter name of its parent
• [x] mixed type
• [x] Throw expression
• [x] Allowing ::class on objects
• [x] Non-capturing catches
• [x] Trailing comma in parameter lists
• [x] Stringable interface (https://github.com/peachpiecompiler/peachpie/commit/32d72d49fd00c84554217fe53198eaa2da4bd6f4)

Functions:

see for latest release status https://docs.peachpie.io/compatibility-status/

• [x] WeakMap
• [x] Attribute
• [x] str_contains, str_starts_with, str_ends_with
• [x] fdiv, get_resource_id
• [x] get_debug_type
• [ ] preg_last_error_msg
• [x] PhpToken
• [ ] resource to Object migration (CurlHandle, CurlMultiHandle, CurlShareHandle, GdImage, Socket, AddressInfo, openssl, XMLWriter, XMLParser)

Others:

• [ ] Calling non-static class methods statically result in a fatal error
• [ ] strict magic method signature
• [x] Locale-independent float to string casting (invariant, we can ignore current context finally!)