US 26-061 11.4.6p10 [class.copy.assign] Redundant specification for defaulted functions

[wg21bot]

The rule about the implicit definition of an explicitly-defaulted function is redundant with the rule in [dcl.fct.def.default]/5.

Proposed change:

Restrict this paragraph to implicitly declared members.

[jensmaurer]

CWG 2022-11-08: Accepted with Modifications. See P2706 cplusplus/papers#1395