Add parserFunction for CodeBlockItem node in CodeGeneration

Author: StevenWong12

CodeGeneration/Sources/SyntaxSupport/CommonNodes.swift

@@ -26,6 +26,7 @@ public let COMMON_NODES: [Node] = [
     nameForDiagnostics: nil,
     description: "A CodeBlockItem is any Syntax node that appears on its own line inside a CodeBlock.",
     kind: "Syntax",
+    parserFunction: "parseCodeBlockItem",
     children: [
       Child(
         name: "Item",

CodeGeneration/Sources/generate-swiftsyntax/templates/swiftparser/ParserEntryFile.swift

@@ -59,17 +59,34 @@ let parserEntryFile = SourceFileSyntax(leadingTrivia: generateCopyrightHeader(fo
 
   for node in SYNTAX_NODES {
     if let parserFunction = node.parserFunction {
-      DeclSyntax(
-        """
-        extension \(raw: node.name): SyntaxParseable {
-          public static func parse(from parser: inout Parser) -> Self {
-            let node = parser.\(raw: parserFunction)()
-            let raw = RawSyntax(parser.parseRemainder(into: node))
-            return Syntax(raw: raw).cast(Self.self)
+      if node.syntaxKind == "CodeBlockItem" {
+        DeclSyntax(
+          """
+          extension \(raw: node.name): SyntaxParseable {
+            public static func parse(from parser: inout Parser) -> Self {
+              guard let node = parser.parseCodeBlockItem() else {
+                assertionFailure("Invalid code block item")
+                return Syntax(raw: RawSyntax(parser.parseCodeBlockItem()!)).cast(Self.self)
+              }
+              let raw = RawSyntax(parser.parseRemainder(into: node))
+              return Syntax(raw: raw).cast(Self.self)
+            }
           }
-        }
-        """
-      )
+          """
+        )
+      } else {
+          DeclSyntax(
+          """
+          extension \(raw: node.name): SyntaxParseable {
+            public static func parse(from parser: inout Parser) -> Self {
+              let node = parser.\(raw: parserFunction)()
+              let raw = RawSyntax(parser.parseRemainder(into: node))
+              return Syntax(raw: raw).cast(Self.self)
+            }
+          }
+          """
+        )
+      }
     }
   }