Replace deprecated stack with list

shared/src/main/scala/scala/xml/dtd/impl/SubsetConstruction.scala:35: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
    val rest = new mutable.Stack[immutable.BitSet]
                           ^
shared/src/main/scala/scala/xml/include/sax/XIncluder.scala:129: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
  private val entities = new mutable.Stack[String]()
                                     ^
shared/src/main/scala/scala/xml/parsing/FactoryAdapter.scala:42: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
  val attribStack = new mutable.Stack[MetaData]
                                ^
shared/src/main/scala/scala/xml/parsing/FactoryAdapter.scala:43: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
  val hStack = new mutable.Stack[Node] // [ element ] contains siblings
                           ^
shared/src/main/scala/scala/xml/parsing/FactoryAdapter.scala:44: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
  val tagStack = new mutable.Stack[String]
                             ^
shared/src/main/scala/scala/xml/parsing/FactoryAdapter.scala:45: class Stack in package mutable is deprecated (since 2.12.0): Stack is an inelegant and potentially poorly-performing wrapper around List. Use a List assigned to a var instead.
  var scopeStack = new mutable.Stack[NamespaceBinding]
                               ^

shared/src/main/scala/scala/xml/dtd/impl/SubsetConstruction.scala

@@ -32,9 +32,9 @@ private[dtd] class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T])
     val delta = new mutable.HashMap[immutable.BitSet, mutable.HashMap[T, immutable.BitSet]]
     val deftrans = mutable.Map(q0 -> sink, sink -> sink) // initial transitions
     val finals: mutable.Map[immutable.BitSet, Int] = mutable.Map()
-    val rest = new mutable.Stack[immutable.BitSet]
+    var rest = immutable.List.empty[immutable.BitSet]
 
-    rest.push(sink, q0)
+    rest = q0 :: sink :: rest
 
     def addFinal(q: immutable.BitSet): Unit = {
       if (nfa containsFinal q)
@@ -43,15 +43,16 @@ private[dtd] class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T])
     def add(Q: immutable.BitSet): Unit = {
       if (!states(Q)) {
         states += Q
-        rest push Q
+        rest = Q :: rest
         addFinal(Q)
       }
     }
 
     addFinal(q0) // initial state may also be a final state
 
     while (!rest.isEmpty) {
-      val P = rest.pop()
+      val P = rest.head
+      rest = rest.tail
       // assign a number to this bitset
       indexMap(P) = ix
       invIndexMap(ix) = P

shared/src/main/scala/scala/xml/factory/XMLLoader.scala

@@ -37,9 +37,9 @@ trait XMLLoader[T <: Node] {
   def loadXML(source: InputSource, parser: SAXParser): T = {
     val newAdapter = adapter
 
-    newAdapter.scopeStack push TopScope
+    newAdapter.scopeStack = TopScope :: newAdapter.scopeStack
     parser.parse(source, newAdapter)
-    newAdapter.scopeStack.pop()
+    newAdapter.scopeStack = newAdapter.scopeStack.tail
 
     newAdapter.rootElem.asInstanceOf[T]
   }

shared/src/main/scala/scala/xml/include/sax/XIncluder.scala

@@ -10,7 +10,6 @@ package scala
 package xml
 package include.sax
 
-import scala.collection.mutable
 import org.xml.sax.{ ContentHandler, Locator, Attributes }
 import org.xml.sax.ext.LexicalHandler
 import java.io.{ OutputStream, OutputStreamWriter, IOException }
@@ -126,7 +125,7 @@ class XIncluder(outs: OutputStream, encoding: String) extends ContentHandler wit
 
   // LexicalHandler methods
   private var inDTD: Boolean = false
-  private val entities = new mutable.Stack[String]()
+  private var entities = List.empty[String]
 
   def startDTD(name: String, publicID: String, systemID: String): Unit = {
     inDTD = true
@@ -146,11 +145,11 @@ class XIncluder(outs: OutputStream, encoding: String) extends ContentHandler wit
   def endDTD(): Unit = {}
 
   def startEntity(name: String): Unit = {
-    entities push name
+    entities =  name :: entities
   }
 
   def endEntity(name: String): Unit = {
-    entities.pop()
+    entities = entities.tail
   }
 
   def startCDATA(): Unit = {}

shared/src/main/scala/scala/xml/parsing/FactoryAdapter.scala

@@ -10,7 +10,6 @@ package scala
 package xml
 package parsing
 
-import scala.collection.{ mutable, Iterator }
 import scala.collection.Seq
 import org.xml.sax.Attributes
 import org.xml.sax.helpers.DefaultHandler
@@ -40,10 +39,10 @@ abstract class FactoryAdapter extends DefaultHandler with factory.XMLLoader[Node
   var rootElem: Node = null
 
   val buffer = new StringBuilder()
-  val attribStack = new mutable.Stack[MetaData]
-  val hStack = new mutable.Stack[Node] // [ element ] contains siblings
-  val tagStack = new mutable.Stack[String]
-  var scopeStack = new mutable.Stack[NamespaceBinding]
+  var attribStack = List.empty[MetaData]
+  var hStack = List.empty[Node] // [ element ] contains siblings
+  var tagStack = List.empty[String]
+  var scopeStack = List.empty[NamespaceBinding]
 
   var curTag: String = null
   var capture: Boolean = false
@@ -123,17 +122,17 @@ abstract class FactoryAdapter extends DefaultHandler with factory.XMLLoader[Node
     attributes: Attributes): Unit =
     {
       captureText()
-      tagStack push curTag
+      tagStack = curTag :: tagStack
       curTag = qname
 
       val localName = splitName(qname)._2
       capture = nodeContainsText(localName)
 
-      hStack push null
+      hStack =  null :: hStack
       var m: MetaData = Null
       var scpe: NamespaceBinding =
         if (scopeStack.isEmpty) TopScope
-        else scopeStack.top
+        else scopeStack.head
 
       for (i <- 0 until attributes.getLength()) {
         val qname = attributes getQName i
@@ -148,16 +147,16 @@ abstract class FactoryAdapter extends DefaultHandler with factory.XMLLoader[Node
           m = Attribute(Option(pre), key, Text(value), m)
       }
 
-      scopeStack push scpe
-      attribStack push m
+      scopeStack = scpe :: scopeStack
+      attribStack =  m :: attribStack
     }
 
   /**
    * captures text, possibly normalizing whitespace
    */
   def captureText(): Unit = {
     if (capture && buffer.length > 0)
-      hStack push createText(buffer.toString)
+      hStack = createText(buffer.toString) :: hStack
 
     buffer.clear()
   }
@@ -171,17 +170,24 @@ abstract class FactoryAdapter extends DefaultHandler with factory.XMLLoader[Node
    */
   override def endElement(uri: String, _localName: String, qname: String): Unit = {
     captureText()
-    val metaData = attribStack.pop()
+    val metaData = attribStack.head
+    attribStack = attribStack.tail
 
     // reverse order to get it right
-    val v = (Iterator continually hStack.pop takeWhile (_ != null)).toList.reverse
+    val v = hStack.takeWhile(_ != null).reverse
+    hStack = hStack.dropWhile(_ != null) match {
+      case null :: hs => hs
+      case hs => hs
+    }
     val (pre, localName) = splitName(qname)
-    val scp = scopeStack.pop()
+    val scp = scopeStack.head
+    scopeStack = scopeStack.tail
 
     // create element
     rootElem = createNode(pre, localName, metaData, scp, v)
-    hStack push rootElem
-    curTag = tagStack.pop()
+    hStack = rootElem :: hStack
+    curTag = tagStack.head
+    tagStack = tagStack.tail
     capture = curTag != null && nodeContainsText(curTag) // root level
   }
 
@@ -190,6 +196,6 @@ abstract class FactoryAdapter extends DefaultHandler with factory.XMLLoader[Node
    */
   override def processingInstruction(target: String, data: String): Unit = {
     captureText()
-    hStack pushAll createProcInstr(target, data)
+    hStack = hStack.reverse_:::(createProcInstr(target, data).toList)
   }
 }