Merge pull request scala#5306 from szeiger/issue/8576

SI-8576 Minimal changes for `-Xcheckinit` compatibility

Author: szeiger

src/library/scala/collection/immutable/Vector.scala

@@ -59,6 +59,7 @@ object Vector extends IndexedSeqFactory[Vector] {
  *  @define mayNotTerminateInf
  *  @define willNotTerminateInf
  */
+@SerialVersionUID(-1334388273712300479L)
 final class Vector[+A] private[immutable] (private[collection] val startIndex: Int, private[collection] val endIndex: Int, focus: Int)
 extends AbstractSeq[A]
    with IndexedSeq[A]

src/repl/scala/tools/nsc/interpreter/PresentationCompilation.scala

@@ -69,7 +69,7 @@ trait PresentationCompilation {
     val interactiveGlobal = new interactive.Global(copySettings, storeReporter) { self =>
       override lazy val platform: ThisPlatform = {
         new JavaPlatform {
-          val global: self.type = self
+          lazy val global: self.type = self
           override private[nsc] lazy val classPath: ClassPath = mergedFlatClasspath
         }
       }