SI-6968 Simple Tuple patterns aren't irrefutable

Reverts part of c82ecab. The parser can't assume that
a pattern `(a, b)` will match, as results of
`.isInstanceOf[Tuple2]` can't be statically known until
after the typer.

The reopens SI-1336, SI-5589 and SI-4574, in exchange for fixing
this regression SI-6968. Keeping all of those fixed will require
a better definition of irrefutability, and some acrobatics to
ensure safe passage to the ambiguous trees through typechecking.

3 files changed, 0 insertions, 56 deletions

diff --git a/test/files/neg/t5589neg.check b/test/files/neg/t5589neg.check
deleted file mode 100644
index f1dad94df3..0000000000
--- a/test/files/neg/t5589neg.check
+++ /dev/null
@@ -1,37 +0,0 @@
-t5589neg.scala:2: warning: `withFilter' method does not yet exist on scala.util.Either.RightProjection[Int,String], using `filter' method instead
-  def f5(x: Either[Int, String])        = for ((y1, y2: String) <- x.right) yield ((y1, y2))
-                                                                     ^
-t5589neg.scala:2: error: constructor cannot be instantiated to expected type;
- found   : (T1, T2)
- required: String
-  def f5(x: Either[Int, String])        = for ((y1, y2: String) <- x.right) yield ((y1, y2))
-                                               ^
-t5589neg.scala:3: warning: `withFilter' method does not yet exist on scala.util.Either.RightProjection[Int,String], using `filter' method instead
-  def f6(x: Either[Int, String])        = for ((y1, y2: Any) <- x.right) yield ((y1, y2))
-                                                                  ^
-t5589neg.scala:3: error: constructor cannot be instantiated to expected type;
- found   : (T1, T2)
- required: String
-  def f6(x: Either[Int, String])        = for ((y1, y2: Any) <- x.right) yield ((y1, y2))
-                                               ^
-t5589neg.scala:4: error: constructor cannot be instantiated to expected type;
- found   : (T1,)
- required: (String, Int)
-  def f7(x: Either[Int, (String, Int)]) = for (y1 @ Tuple1(y2) <- x.right) yield ((y1, y2))
-                                                    ^
-t5589neg.scala:4: error: not found: value y2
-  def f7(x: Either[Int, (String, Int)]) = for (y1 @ Tuple1(y2) <- x.right) yield ((y1, y2))
-                                                                                       ^
-t5589neg.scala:5: error: constructor cannot be instantiated to expected type;
- found   : (T1, T2, T3)
- required: (String, Int)
-  def f8(x: Either[Int, (String, Int)]) = for ((y1, y2, y3) <- x.right) yield ((y1, y2))
-                                               ^
-t5589neg.scala:5: error: not found: value y1
-  def f8(x: Either[Int, (String, Int)]) = for ((y1, y2, y3) <- x.right) yield ((y1, y2))
-                                                                                ^
-t5589neg.scala:5: error: not found: value y2
-  def f8(x: Either[Int, (String, Int)]) = for ((y1, y2, y3) <- x.right) yield ((y1, y2))
-                                                                                    ^
-two warnings found
-7 errors found
diff --git a/test/files/neg/t5589neg.scala b/test/files/neg/t5589neg.scala
deleted file mode 100644
index 31ff2c3693..0000000000
--- a/test/files/neg/t5589neg.scala
+++ /dev/null
@@ -1,6 +0,0 @@
-class A {
-  def f5(x: Either[Int, String])        = for ((y1, y2: String) <- x.right) yield ((y1, y2))
-  def f6(x: Either[Int, String])        = for ((y1, y2: Any) <- x.right) yield ((y1, y2))
-  def f7(x: Either[Int, (String, Int)]) = for (y1 @ Tuple1(y2) <- x.right) yield ((y1, y2))
-  def f8(x: Either[Int, (String, Int)]) = for ((y1, y2, y3) <- x.right) yield ((y1, y2))
-}
diff --git a/test/files/neg/t5589neg2.scala b/test/files/neg/t5589neg2.scala
deleted file mode 100644
index b7c7ab7218..0000000000
--- a/test/files/neg/t5589neg2.scala
+++ /dev/null
@@ -1,13 +0,0 @@
-class A {
-  def f1(x: List[((((Int, (Double, (Float, String))), List[String]), List[Int]), List[Float])]) = {
-    for (((((a, (b, (c, d))), es), fs), gs) <- x) yield (d :: es).mkString(", ") // ok
-  }
-
-  def f2(x: List[((((Int, (Double, (Float, String))), List[String]), List[Int]), List[Float])]) = {
-    for (((((a, (b, (c, (d1, d2)))), es), fs), gs) <- x) yield (d :: es).mkString(", ") // not ok
-  }
-
-  def f3(x: List[((((Int, (Double, (Float, String))), List[String]), List[Int]), List[Float])]) = {
-    for (((((a, (b, _)), es), fs), gs) <- x) yield (es ::: fs).mkString(", ") // ok
-  }
-}
\ No newline at end of file