Pattern matching in `val` and `match` return different types

[Atry]

According to Scala language specification 4.1, the following code should have the same behavior:

Welcome to Scala 2.12.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_102).
Type in expressions for evaluation. Or try :help.

scala> val (a: Any, b: Any) = (1, 2) 
a: Any = 1
b: Any = 2

Welcome to Scala 2.12.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_102).
Type in expressions for evaluation. Or try :help.

scala> val $x = (1, 2) match { case (a: Any, b: Any) => (a, b) }; val a = $x._1; val b = $x._2 
$x: (Int, Int) = (1,2)
a: Int = 1
b: Int = 2

However, the type of a and b are different in the two examples.

[som-snytt]

In dotty, the match expression is correct:

scala> val vs = ("1", "2") match { case (a: Any, b: Any) => (a, b) }
val vs: (Any, Any) = (1,2)