fixup! Allow @Metadata directives in doc comments

Author: franklinsch

Tests/SwiftDocCTests/Semantics/SymbolTests.swift

@@ -492,7 +492,7 @@ class SymbolTests: XCTestCase {
         XCTAssertEqual(withRedirectInArticle.redirects, nil)
 
         XCTAssertEqual(problems.first?.diagnostic.identifier, "org.swift.docc.UnsupportedDocCommentDirective")
-        XCTAssertEqual(problems.first?.diagnostic.range?.lowerBound.line, 15)
+        XCTAssertEqual(problems.first?.diagnostic.range?.lowerBound.line, 3)
         XCTAssertEqual(problems.first?.diagnostic.range?.lowerBound.column, 1)
     }
 
@@ -1225,6 +1225,7 @@ class SymbolTests: XCTestCase {
 
                 @Metadata
                 """,
+            docCommentLineOffset: 12,
             articleContent: nil,
             diagnosticEngineFilterLevel: .information
         )
@@ -1247,6 +1248,7 @@ class SymbolTests: XCTestCase {
                   @Available("Platform from doc comment", introduced: 1.2.3)
                 }
                 """,
+            docCommentLineOffset: 12,
             articleContent: """
             # Title
             
@@ -1354,6 +1356,7 @@ class SymbolTests: XCTestCase {
 
     func makeDocumentationNodeForSymbol(
         docComment: String,
+        docCommentLineOffset: Int = 0,
         articleContent: String?,
         diagnosticEngineFilterLevel: DiagnosticSeverity = .warning,
         file: StaticString = #file,
@@ -1363,21 +1366,15 @@ class SymbolTests: XCTestCase {
         let (_, bundle, context) = try testBundleAndContext(copying: "LegacyBundle_DoNotUseInNewTests") { url in
             var graph = try JSONDecoder().decode(SymbolGraph.self, from: Data(contentsOf: url.appendingPathComponent("mykit-iOS.symbols.json")))
 
-            let newDocComment = SymbolGraph.LineList(
-                docComment
-                    .components(separatedBy: .newlines)
-                    .enumerated()
-                    .map { arg -> SymbolGraph.LineList.Line in
-                        var (index, line) = arg
-                        index += 12 // Add an arbitrary offset
-                        let range = SymbolGraph.LineList.SourceRange(
-                            start: .init(line: index, character: 0),
-                            end: .init(line: index, character: line.utf8.count)
-                        )
-                        return .init(text: line, range: range)
-                    },
-                uri: "file:///tmp/File.swift"
+            let newDocComment = self.makeLineList(
+                docComment: docComment,
+                startOffset: .init(
+                    line: docCommentLineOffset,
+                    character: 0
+                ),
+                url: URL(string: "file:///tmp/File.swift")!
             )
+            
             // The `guard` statement` below will handle the `nil` case by failing the test and
             graph.symbols[myFunctionUSR]?.docComment = newDocComment