work around optimizer bug SI-5672

the optimizer generates wrong bytecode for switches in arguments
virtpatmat happily emits a switch for a one-case switch, whereas -Xoldpatmat did not
this is not the focus of this test, hence the temporary workaround

test/files/run/t3835.scala

@@ -1,4 +1,9 @@
 object Test extends App {
-  println((1, 2, 3) match { case (r, \u03b8, \u03c6) => r + \u03b8 + \u03c6 })
-  println(1 match { case \u00e9 => \u00e9 })
+  // work around optimizer bug SI-5672  -- generates wrong bytecode for switches in arguments
+  // virtpatmat happily emits a switch for a one-case switch, whereas -Xoldpatmat did not
+  // this is not the focus of this test, hence the temporary workaround
+  def a = (1, 2, 3) match { case (r, \u03b8, \u03c6) => r + \u03b8 + \u03c6 }
+  println(a)
+  def b = (1 match { case \u00e9 => \u00e9 })
+  println(b)
 }