work around scala/bug#11152 on JDK 11

Author: SethTisue

scalatest/src/main/scala/org/scalatest/Doc.scala

@@ -144,7 +144,8 @@ println("&&&&&&&&&&&")
 
   private[scalatest] def getSnippets(text: String): Vector[Snippet] = {
 //println("text: " + text)
-    val lines = Vector.empty ++ text.lines.toIterable
+    // work around scala/bug#11152 on JDK 11
+    val lines = Vector.empty ++ Predef.augmentString(text).lines.toIterable
 //println("lines: " + lines)
     val pairs = lines map { line =>
       val trimmed = line.trim
@@ -186,7 +187,8 @@ println("&&&&&&&&&&&")
 private[scalatest] object Doc {
 
   private[scalatest] def trimMarkup(text: String): String = {
-    val lines = text.lines.toList
+    // work around scala/bug#11152 on JDK 11
+    val lines = Predef.augmentString(text).lines.toList
     val zipLines = lines.zipWithIndex
     val firstNonWhiteLine = zipLines.find { case (line, _) => !line.trim.isEmpty }
     val lastNonWhiteLine = zipLines.reverse.find { case (line, _) => !line.trim.isEmpty } 
@@ -197,7 +199,8 @@ private[scalatest] object Doc {
   }
 
   private[scalatest] def stripMargin(text: String): String = {
-    val lines = text.lines.toList
+    // work around scala/bug#11152 on JDK 11
+    val lines = Predef.augmentString(text).lines.toList
     val firstNonWhiteLine = lines.find(!_.trim.isEmpty)
     firstNonWhiteLine match {
       case None => text.trim

scalatest/src/main/scala/org/scalatest/DocSpec.scala

@@ -41,7 +41,8 @@ private[scalatest] abstract class DocSpec extends DocSpecLike {
 private[scalatest] object DocSpec {
 
   def trimMarkup(text: String): String = {
-    val lines = text.lines.toList
+    // work around scala/bug#11152 on JDK 11
+    val lines = Predef.augmentString(text).lines.toList
     val zipLines = lines.zipWithIndex
     val firstNonWhiteLine = zipLines.find { case (line, _) => !line.trim.isEmpty }
     val lastNonWhiteLine = zipLines.reverse.find { case (line, _) => !line.trim.isEmpty } 
@@ -52,7 +53,8 @@ private[scalatest] object DocSpec {
   }
 
   def stripMargin(text: String): String = {
-    val lines = text.lines.toList
+    // work around scala/bug#11152 on JDK 11
+    val lines = Predef.augmentString(text).lines.toList
     val firstNonWhiteLine = lines.find(!_.trim.isEmpty)
     firstNonWhiteLine match {
       case None => text.trim