Missing relevance check for select in patterns

[liufengyun]

Arguably, all of them should be invalid.

    val x = 42
    val Y = "h"

    x match { case { "h" }.toString => println(42) }  // ok
    x match { case { "h".toString } => println(42) }  // error
    x match { case Y => println(42) }  // error
    x match { case Y.toString => println(42) }  // ok

[allanrenucci]

As pointed out in #3810, even though some of these patterns compile, they do not pass Ycheck