Allow parsing for enum case element parameter on new line

Author: kimdv

Sources/SwiftParser/Declarations.swift

@@ -918,7 +918,7 @@ extension Parser {
         let (unexpectedBeforeName, name) = self.expectIdentifier(keywordRecovery: true)
 
         let associatedValue: RawEnumCaseParameterClauseSyntax?
-        if self.at(TokenSpec(.leftParen, allowAtStartOfLine: false)) {
+        if self.at(TokenSpec(.leftParen)) {
           associatedValue = self.parseParameterClause(RawEnumCaseParameterClauseSyntax.self) { parser in
             parser.parseEnumCaseParameter()
           }

Tests/SwiftParserTest/DeclarationTests.swift

@@ -26,6 +26,7 @@ final class DeclarationTests: XCTestCase {
 
     assertParse(#"@_private(sourceFile: "YetAnotherFile.swift") import Foundation"#)
   }
+
   func testStructParsing() {
     assertParse("struct Foo {}")
   }

Tests/SwiftParserTest/translated/EnumTests.swift

@@ -1450,4 +1450,15 @@ final class EnumTests: XCTestCase {
       """#
     )
   }
+
+  func parseEnumCaseElementParameterOnNewline() {
+    assertParse(
+      """
+      enum E {
+        case a
+          (Int)
+      }
+      """
+    )
+  }
 }