Merge pull request scala#5986 from retronym/ticket/9146

Test case for already-fixed pattern matcher bug

Author: lrytz

test/files/run/t9146.scala

@@ -0,0 +1,26 @@
+trait A {
+  val value: String
+}
+
+trait B {
+  val as: List[A]
+}
+
+case class C(value: String) extends A
+
+object Test {
+  object test extends B {
+    val as = List(
+      new C("one") {},
+      new C("two") {}
+    )
+
+    def method = as match {
+      case List(C("one"), _) => 1
+      case _ => 42
+    }
+  }
+  def main(args: Array[String]): Unit = {
+    assert(test.method == 1)
+  }
+}