* InternPool: replace untyped values with typed values
* InternPool: remove `indexToTag`
* InternPool: rework representation of optional values
* add representation for unknown values and types
* ComptimeInterpreter: use InternPool typed-values
* ComptimeInterpreter: field access test
* ComptimeInterpreter: improve handling of if expressions
* InternPool: fix typeOf on a comptime float
* ComptimeInterpreter: implement TypeOf with multiple parameters