Fix compilation with JDK 11

The extension method lines is now shadowed by String#lines that returns
a Stream, use linesIterator instead (it used to be deprecated in favor
of lines, but has been undeprecated in 2.12.7)

compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala

@@ -91,15 +91,15 @@ trait MessageRendering {
     * @return aligned error message
     */
   def errorMsg(pos: SourcePosition, msg: String, offset: Int)(implicit ctx: Context): String = {
-    val padding = msg.lines.foldLeft(pos.startColumnPadding) { (pad, line) =>
+    val padding = msg.linesIterator.foldLeft(pos.startColumnPadding) { (pad, line) =>
       val lineLength = stripColor(line).length
       val maxPad = math.max(0, ctx.settings.pageWidth.value - offset - lineLength) - offset
 
       if (maxPad < pad.length) " " * maxPad
       else pad
     }
 
-    msg.lines
+    msg.linesIterator
       .map { line => " " * (offset - 1) + "|" + padding + line}
       .mkString(sys.props("line.separator"))
   }

compiler/test/dotty/tools/vulpix/ParallelTesting.scala

@@ -613,7 +613,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
       else runMain(testSource.runClassPath) match {
         case Success(_) if !checkFile.isDefined || !checkFile.get.exists => // success!
         case Success(output) => {
-          val outputLines = output.lines.toArray :+ DiffUtil.EOF
+          val outputLines = output.linesIterator.toArray :+ DiffUtil.EOF
           val checkLines: Array[String] = Source.fromFile(checkFile.get).getLines().toArray :+ DiffUtil.EOF
           val sourceTitle = testSource.title
 
@@ -1027,7 +1027,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
         case test.TimeoutFailure(title) =>
           s"  - test '$title' timed out"
         case test.JavaCompilationFailure(msg) =>
-          s"  - java compilation failed with:\n${ msg.lines.map("      " + _).mkString("\n") }"
+          s"  - java compilation failed with:\n${ msg.linesIterator.map("      " + _).mkString("\n") }"
       }.mkString("\n")
     }
 

doc-tool/src/dotty/tools/dottydoc/model/comment/CommentCleaner.scala

@@ -21,6 +21,6 @@ trait CommentCleaner {
       SafeTags.replaceAllIn(javadoclessComment, { mtch =>
         Matcher.quoteReplacement(safeTagMarker + mtch.matched + safeTagMarker)
       })
-    markedTagComment.lines.toList map (cleanLine)
+    markedTagComment.linesIterator.toList map (cleanLine)
   }
 }

doc-tool/src/dotty/tools/dottydoc/staticsite/Page.scala

@@ -115,7 +115,7 @@ trait Page {
     val withoutYaml = virtualFile(
       if (content.startsWith("---\n")) {
         val str =
-          content.lines
+          content.linesIterator
           .drop(1)
           .dropWhile(line => line != "---" && line != "...")
           .drop(1).mkString("\n")

tests/run/richs.scala

@@ -75,11 +75,11 @@ object RichStringTest1 extends RichTest {
 object RichStringTest2 extends RichTest {
   def run: Unit = {
     println("\n" + getObjectName + ":")
-    Console.print("s1: "); s1.lines foreach println
-    Console.print("s2: "); s2.lines foreach println
-    Console.print("s3: "); s3.lines foreach println
-    Console.print("s4: "); s4.lines foreach println
-    Console.print("s5: "); s5.lines foreach println
+    Console.print("s1: "); s1.linesIterator foreach println
+    Console.print("s2: "); s2.linesIterator foreach println
+    Console.print("s3: "); s3.linesIterator foreach println
+    Console.print("s4: "); s4.linesIterator foreach println
+    Console.print("s5: "); s5.linesIterator foreach println
   }
 }
 object RichStringTest3 extends RichTest {

tests/run/t8015-ffc.scala

@@ -2,6 +2,6 @@
 object Test extends dotty.runtime.LegacyApp {
   val ms = """This is a long multiline string
   with \u000d\u000a CRLF embedded."""
-  assert(ms.lines.size == 3, s"lines.size ${ms.lines.size}")
+  assert(ms.linesIterator.size == 3, s"lines.size ${ms.linesIterator.size}")
   assert(ms contains "\r\n CRLF", "no CRLF")
 }