Drop CaseIterable

Author: DougGregor

Sources/SwiftRefactor/IntegerLiteralUtilities.swift

@@ -17,7 +17,7 @@ import SwiftSyntax
 #endif
 
 extension IntegerLiteralExprSyntax {
-  public enum Radix: CaseIterable {
+  public enum Radix {
     case binary
     case octal
     case decimal