Now that we support multiple related spans for errors (#10489, #22789, #24548), we'd like to improve an existing error message. Currently, we provide certain errors for when a derived type incorrectly overrides/implements a member from the base type: ``` Class '{0}' defines instance member function '{1}', but extended class '{2}' defines it as instance member accessor. Class '{0}' defines instance member function '{1}', but extended class '{2}' defines it as instance member property. Class '{0}' defines instance member property '{1}', but extended class '{2}' defines it as instance member function. Class '{0}' defines instance member accessor '{1}', but extended class '{2}' defines it as instance member function. Property '{0}' in type '{1}' is not assignable to the same property in base type '{2}'. ``` We can actually provide the base type's member as a related span location for some extra context. ``` '{0}' redefines '{1}' in an incompatible way. ``` Where * `0` is the derived type * `1` is the member name and this gets reported on the base type member.