Move all pickling tests to pos

Move pickling/annot.scala to pending as it doesn't pass Ycheck,
see scala#5073.

Author: OlivierBlanvillain

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -183,7 +183,6 @@ class CompilationTests extends ParallelTesting {
   @Test def pickling: Unit = {
     implicit val testGroup: TestGroup = TestGroup("testPickling")
     compileFilesInDir("tests/new", picklingOptions) +
-    compileFilesInDir("tests/pickling", picklingOptions) +
     compileFilesInDir("tests/pos", picklingOptions, FileFilter.exclude(TestSources.posTestPicklingBlacklisted)) +
     compileFilesInDir("tests/run", picklingOptions, FileFilter.exclude(TestSources.runTestPicklingBlacklisted))
   }.checkCompile()

tests/pickling/annot.scala renamed to tests/pending/annot-2.scala

@@ -5,6 +5,7 @@ class RefinedType extends Type
 object TestAnnot {
   def toText(tp: Type) = tp match {
     case tp: RefinedType =>
+      // Doesn't Ycheck, see #5073
       val parent :: (refined: List[RefinedType @unchecked]) = ???
       ???
   }