Unify Named with ThriftType about thrifty

[benjamin-bader]

You and I arrived at the same conclusion; I've ended up with both TypedefType and ServiceType extending UserType. The final hierarchy, then, is

ThriftType
|__BuiltinType (bool,byte,i8,i16,i32,i64,double,string,binary)
|__ListType
|__SetType
|__MapType
|__UserType
|  |__EnumType
|  |__StructType (struct, union, exception)
|  |__TypedefType
|  |__ServiceType

[benjamin-bader]

So - the proposed hierarchy would be:

ThriftType
|__BuiltinThriftType (bool,byte,i8,i16,i32,i64,double,string,binary)
|__ListThriftType
|__SetThriftType
|__MapThriftType
|__TypedefThriftType
|__UserThriftType
|  |__EnumThriftType
|  |__StructThriftType (struct, union, exception)
|__ServiceThriftType

UserThriftType and ServiceThriftType, and Constant will tentatively implement an interface exposing the same things that Named does currently - Location and Javadoc.

Program would be more or less the same, but everything from Linker down changes. Codegen will presumably be different, though I haven't thought much about it.

[ZacSweers]

After what we discussed about Typedefs, should they maybe straddle the line with UserThriftType a bit more?