Avoid conversion from StaticType to sema.Type during runtime sub-type checking

[SupunS]

Issue to be solved

In Interpreter.IsSubType(...) function, both the sub-type and the super-type gets converted from StaticType to sema.Type (see below). This adds an unnecessary overhead.

cadence/interpreter/interpreter.go

Line 4066 in b09231f

semaSubType := interpreter.MustConvertStaticToSemaType(staticSubType)

cadence/interpreter/interpreter.go

Line 4039 in b09231f

semaType := interpreter.MustConvertStaticToSemaType(superType)

Suggested Solution

Having a separate sub-type checking implementation for runtime (static types) could eliminate this overhead. We could define the sub-typing rules in some declarative format, and then generate the two implementations from that, to make them consistent/in-sync.