Readd .widen which was accidentally removed from the previous commit

Author: smarter

src/dotty/tools/dotc/typer/Typer.scala

@@ -1266,7 +1266,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
   def adapt(tree: Tree, pt: Type, original: untpd.Tree = untpd.EmptyTree)(implicit ctx: Context) = /*>|>*/ track("adapt") /*<|<*/ {
     /*>|>*/ ctx.traceIndented(i"adapting $tree of type ${tree.tpe} to $pt", typr, show = true) /*<|<*/ {
       if (tree.isDef) interpolateUndetVars(tree, tree.symbol)
-      else if (!tree.tpe.isInstanceOf[MethodOrPoly]) interpolateUndetVars(tree, NoSymbol)
+      else if (!tree.tpe.widen.isInstanceOf[MethodOrPoly]) interpolateUndetVars(tree, NoSymbol)
       tree.overwriteType(tree.tpe.simplified)
       adaptInterpolated(tree, pt, original)
     }