Describe the Bug

See the sandbox link: variable y is correctly determined to be y: Self@SomeClass, however variable x on return shows x: Self Returned type 'Self' is not assignable to declared return type 'Self@SomeClass'
When using generics, and retrieving Self from some form of cache, pyrefly loses some context about Self and throws this Error:

TODO: bool attribute base undefined for type: Self (trying to access bool)
Sorry, Pyrefly encountered an internal error, this is always a bug in Pyrefly itself
Please report the bug at https://github.com/facebook/pyrefly/issues/new
Pyreflyinternal-error`

version: Pyrefly 0.50.0

Sandbox Link

https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEALqcROgOZ0Q3G6UN0BlGFDAAddOIDGUVHDiDaMAMIy5icXU11JqSQAsYdALx1MESQwDarBgBpBwsAF0AFAEpxGrZhhg6bGAYAfVY4BgxJGBc4Rzc6AFoAPgcRdXQtDM4-fDpEExiRQh19GEsABicvTMzKQIBXSnT8KsyIP1Jc-Mc06urahgb00haMmjgOE1EQADlcTnQwiMMwXDqsKZGtSlQIGLoANVQoOpgAUUpqShcxtg90EFsQOoZoOBJyRBAAYjoAVReoBAmHQwGsLBBcAtPFhfCDeDRUMF0HUaNgYFd8Ih5gw4kk6GFKD0tvVGiCptMUWjCXRgPgAL4be6PMi1MBQUiEBi0KAUH4ABVIrPZ%2BIwOAI2khkDYDUREPQhHEPyEhj0DAYxDgiAA9FqWb52YReGwtTB0FrMLhJHAtZJJRBpdsXpCtXDKHRUAA3HYybCwCXoKUyp3pXDEYNvcRkBh6SHxD3ouBy4x0KYAZkIAEYAEyMkB0x66F7xgBi0BgFDQWDwRDIeaAA

(Only applicable for extension issues) IDE Information

No response