Fixes #1856: mimic Scalac sematic of recursive lazy vals.

Author: DarkDimius

compiler/src/dotty/tools/dotc/transform/LazyVals.scala

@@ -186,8 +186,9 @@ class LazyVals extends MiniPhaseTransform with IdentityDenotTransformer {
 
     def mkNonThreadSafeDef(target: Tree, flag: Tree, rhs: Tree)(implicit ctx: Context) = {
       val setFlag = flag.becomes(Literal(Constants.Constant(true)))
-      val setTargets = if (isWildcardArg(rhs)) Nil else target.becomes(rhs) :: Nil
-      val init = Block(setFlag :: setTargets, target.ensureApplied)
+      val flagSet = setFlag :: Nil
+      val targetSet = if (isWildcardArg(rhs)) flagSet else target.becomes(rhs) :: flagSet
+      val init = Block(targetSet, target.ensureApplied)
       If(flag.ensureApplied, target.ensureApplied, init)
     }