Bypass builtins deserialization mechanism in legacy JS backend and load
bultins direcly as kotlin code.
This way we won't have separated IR declarations for Enum, Char, Long
Some "native" builtins are implemented in libraries/stdlib/js/irRuntime/builtins/
Other builtins are moved by MoveExternalDeclarationsToSeparatePlace and
used only in compile-time
Svyatoslav Kuzmich