Add regression test for a fixed crasher

This test case was also posted by a developer in
https://bugs.swift.org/browse/SR-11153, but it appears to
be a different problem that was fixed in Swift 5.2.

Author: slavapestov

validation-test/compiler_crashers_2_fixed/Inputs/sr11153_2_other.swift

@@ -0,0 +1,17 @@
+protocol Snapshotting {
+    associatedtype NativeType: NativeInserting where NativeType.SnapshotType == Self
+    associatedtype ChangeType: SnapshotChange where ChangeType.SnapshotType == Self
+}
+
+protocol NativeInserting {
+    associatedtype SnapshotType : Snapshotting where SnapshotType.NativeType == Self
+}
+
+protocol SnapshotProperties : OptionSet where RawValue == Int {
+    static var all: Self { get }
+}
+
+protocol SnapshotChange {
+    associatedtype SnapshotType : Snapshotting where SnapshotType.ChangeType == Self
+    associatedtype PropertiesType : SnapshotProperties
+}

validation-test/compiler_crashers_2_fixed/sr11153_2.swift

@@ -0,0 +1,15 @@
+// RUN: %target-swift-frontend -emit-ir -primary-file %S/Inputs/sr11153_2_other.swift -primary-file %s
+// RUN: %target-swift-frontend -emit-ir %S/Inputs/sr11153_2_other.swift %s
+
+class WatchRegistry {
+    func single<S: Snapshotting>(objectType: S.Type) throws -> Watch<S>
+    {
+        return try Watch<S>.singleObject(objectType: S.self, properties: S.ChangeType.PropertiesType.all)
+    }
+}
+
+class Watch<SnapshotType : Snapshotting> {
+    static func singleObject(objectType: SnapshotType.Type, properties: SnapshotType.ChangeType.PropertiesType) throws -> Watch<SnapshotType> {
+        fatalError()
+    }
+}