Merge pull request swiftlang#23749 from slavapestov/add-regression-tests

Add regression test for fixed bugs

Author: slavapestov

validation-test/compiler_crashers_2_fixed/0191-sr9508.swift

@@ -0,0 +1,20 @@
+// RUN: %target-swift-frontend -typecheck %s
+
+protocol P {
+    associatedtype A
+}
+
+struct S1: P {
+    typealias A = Int
+}
+
+struct S2<G: P>: P {
+    typealias A = G.A
+}
+
+struct S3<G: P> {
+}
+
+extension S3 where G == S2<S1> {
+    typealias B = G.A
+}

validation-test/compiler_crashers_2_fixed/0192-rdar39826863.swift

@@ -0,0 +1,34 @@
+// RUN: %target-swift-frontend -typecheck %s
+
+protocol Tuple {
+  associatedtype Head
+  associatedtype Tail : Tuple
+}
+
+extension Pair : Tuple where Second : Tuple {
+  typealias Head = First
+  typealias Tail = Second
+}
+
+protocol HomogeneousTuple : Tuple, Collection
+  where Tail : HomogeneousTuple, Head == Tail.Head {}
+
+extension HomogeneousTuple {
+  typealias Element = Head
+  typealias Index = Int
+
+  var startIndex: Int { return 0 }
+  var endIndex: Int { return 0 }
+  func index(after i: Int) -> Int { return i + 1 }
+
+  subscript(n: Int) -> Head {
+      fatalError()
+  }
+}
+
+extension Pair : Sequence, Collection, HomogeneousTuple
+  where Second : HomogeneousTuple, First == Second.Head {
+  typealias Iterator = IndexingIterator<Pair<Head, Tail>>
+}
+
+struct Pair<First, Second> {}