swift

19831722 - [Sema] Rename `bindSwitchCasePatternVars` -> `diagnoseCaseVarMutabilityMismatch`

[Sema] Rename `bindSwitchCasePatternVars` -> `diagnoseCaseVarMutabilityMismatch` Now that we wire up the parents up-front, this no longer needs to set the parents. As such, remove the logic and rename to reflect the fact that it now just diagnoses mutability mismatches.