Add isDeprecated to Node

Author: kimdv

CodeGeneration/Sources/SyntaxSupport/Node.swift

@@ -57,6 +57,9 @@ public class Node {
   /// function that should be invoked to create this node.
   public let parserFunction: TokenSyntax?
 
+  /// If `true`, if the node is deprecated and should not be used anymore.
+  public let isDeprecated: Bool
+
   /// If `true`, this is for an experimental language feature, and any public
   /// API generated should be SPI.
   public var isExperimental: Bool { experimentalFeature != nil }
@@ -106,10 +109,16 @@ public class Node {
           """
         experimentalSPI.with(\.trailingTrivia, .newline)
       }
+
       if forRaw {
         "@_spi(RawSyntax)"
       }
+
+      if isDeprecated {
+        #"@available(*, deprecated, message: "This node is longer being generated by the parser.")"#
+      }
     }
+
     return attrList.with(\.trailingTrivia, attrList.isEmpty ? [] : .newline)
   }
 
@@ -128,6 +137,7 @@ public class Node {
     kind: SyntaxNodeKind,
     base: SyntaxNodeKind,
     experimentalFeature: ExperimentalFeature? = nil,
+    isDeprecated: Bool = false,
     nameForDiagnostics: String?,
     documentation: String? = nil,
     parserFunction: TokenSyntax? = nil,
@@ -140,6 +150,7 @@ public class Node {
     self.kind = kind
     self.base = base
     self.experimentalFeature = experimentalFeature
+    self.isDeprecated = isDeprecated
     self.nameForDiagnostics = nameForDiagnostics
     self.documentation = SwiftSyntax.Trivia.docCommentTrivia(from: documentation)
     self.parserFunction = parserFunction
@@ -272,6 +283,7 @@ public class Node {
     kind: SyntaxNodeKind,
     base: SyntaxNodeKind,
     experimentalFeature: ExperimentalFeature? = nil,
+    isDeprecated: Bool = false,
     nameForDiagnostics: String?,
     documentation: String? = nil,
     parserFunction: TokenSyntax? = nil,
@@ -281,6 +293,7 @@ public class Node {
     precondition(base == .syntaxCollection)
     self.base = base
     self.experimentalFeature = experimentalFeature
+    self.isDeprecated = isDeprecated
     self.nameForDiagnostics = nameForDiagnostics
     self.documentation = SwiftSyntax.Trivia.docCommentTrivia(from: documentation)
     self.parserFunction = parserFunction