SI-8035 Deprecate automatic () insertion in argument lists

This promotes the () insertion warning from -Ywarn-adapted-args to a
deprecation warning. -Xfuture tunrs it into a compiler error.

Auto tupling remains unchanged for now.

The tests have been fixed the following way:
- Warnings caused by general sloppiness (Try(), Future(), ...) have been
  fixed.
- Warnings which raise interesting questions (x == (), ...) received an
  updated checkfile for now.

1 files changed, 4 insertions, 4 deletions

diff --git a/test/files/neg/t4851.check b/test/files/neg/t4851.check
index 4f2919807e..132dd91b50 100644
--- a/test/files/neg/t4851.check
+++ b/test/files/neg/t4851.check
@@ -1,10 +1,10 @@
-S.scala:2: warning: Adapting argument list by inserting (): leaky (Object-receiving) target makes this especially dangerous.
+S.scala:2: warning: Adaptation of argument list by inserting () has been deprecated: leaky (Object-receiving) target makes this especially dangerous.
         signature: J(x: Any): J
   given arguments: <none>
  after adaptation: new J((): Unit)
   val x1 = new J
            ^
-S.scala:3: warning: Adapting argument list by inserting (): leaky (Object-receiving) target makes this especially dangerous.
+S.scala:3: warning: Adaptation of argument list by inserting () has been deprecated: leaky (Object-receiving) target makes this especially dangerous.
         signature: J(x: Any): J
   given arguments: <none>
  after adaptation: new J((): Unit)
@@ -28,13 +28,13 @@ S.scala:7: warning: Adapting argument list by creating a 3-tuple: this may not b
  after adaptation: new Some((1, 2, 3): (Int, Int, Int))
   val y2 = new Some(1, 2, 3)
            ^
-S.scala:9: warning: Adapting argument list by inserting (): this is unlikely to be what you want.
+S.scala:9: warning: Adaptation of argument list by inserting () has been deprecated: this is unlikely to be what you want.
         signature: J2[T](x: T): J2[T]
   given arguments: <none>
  after adaptation: new J2((): Unit)
   val z1 = new J2
            ^
-S.scala:10: warning: Adapting argument list by inserting (): this is unlikely to be what you want.
+S.scala:10: warning: Adaptation of argument list by inserting () has been deprecated: this is unlikely to be what you want.
         signature: J2[T](x: T): J2[T]
   given arguments: <none>
  after adaptation: new J2((): Unit)