Remove @frozen from TokenKind

Author: ahoppen

CodeGeneration/Sources/generate-swiftsyntax/templates/swiftsyntax/TokenKindFile.swift

@@ -19,7 +19,6 @@ let tokenKindFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
   try! EnumDeclSyntax(
     """
     /// Enumerates the kinds of tokens in the Swift language.
-    @frozen // FIXME: Not actually stable, works around a miscompile
     public enum TokenKind: Hashable
     """
   ) {

Sources/SwiftSyntax/generated/TokenKind.swift

@@ -13,7 +13,6 @@
 //===----------------------------------------------------------------------===//
 
 /// Enumerates the kinds of tokens in the Swift language.
-@frozen // FIXME: Not actually stable, works around a miscompile
 public enum TokenKind: Hashable {
   case eof
   case arrow