swift234

[SR-560] reinstate bound generic type assert

This assertion was accidentally removed in the commit below:

<https://github.com/apple/swift/commit/32bd7705bffb24c11b6b04ecd635a8f6c7586744>

The original purpose of the check was to ensure that unbound generic patterns
are never added to protocol conformance records, only to type metadata records
(where they are present a future implementation of dynamic type
specialization).