5f34cb34b2
scriptvalue.h/.c holds the scriptvalue_t tagged-union type and its JS<->C decode/encode helpers; scriptdef.h/.c holds the declarative scriptfuncdef_t/scriptpropdef_t definitions, the binding registry, and the JerryScript trampolines. Lets a module declare its JS-facing methods/properties/globals as typed data instead of hand-writing argument-checking boilerplate per method. Framework only for now -- no existing module has been migrated onto it yet.