Fix typo in Bridges

Author: natsukagami

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

@@ -133,7 +133,7 @@ class Bridges(root: ClassSymbol, thisPhase: DenotTransformer)(using Context) {
           val anonFun = newAnonFun(ctx.owner,
             MethodType(
               argTypes.zip(isErased.padTo(argTypes.length, false))
-                      .flatMap((t, e) => if e then List(t) else List()),
+                      .flatMap((t, e) => if e then None else Some(t)),
               resType),
             coord = ctx.owner.coord)
           anonFun.info = transformInfo(anonFun, anonFun.info)