Idea: Can declaration emit synthesize type aliases?

Object types can be very large and in (e.g.) a react project that makes heavy use of type inference, it's not uncommon to have to refer to a type that is either not imported or is simply anonymous (e.g. a props type). When these appear in multiple places in a declaration file, they tend to expand it considerably. Perhaps we could just synthesize type aliases for them?

• We'd have to be careful not to change the exported API shape
• We could use a heuristic to skip the work for small types (e.g. < 20 characters)
• Even if we didn't wait until the second use of a type to decide to extract it, we'd be adding ~4 tokens per type (type id = and id at the use site)

El issue propone sintetizar alias de tipo durante la emisión de declaraciones para tipos de objeto anónimos grandes que se repiten. No se nombran archivos, pruebas ni puntos de entrada; primero hay que trazar la implementación de la emisión de declaraciones y evaluar la heurística de tamaño indicada. Se considera completado cuando se reduzca la expansión de los archivos de declaración sin cambiar la forma de la API exportada.