Merge pull request #1040 from practicalswift/swiftc-28222-swift-typechecker-checkconformance

[swiftc] Add test case for crash triggered in swift::TypeChecker::checkConformance(…)

Author: gribozavr

validation-test/compiler_crashers/28222-swift-typechecker-checkconformance.swift

@@ -0,0 +1,8 @@
+// RUN: not --crash %target-swift-frontend %s -parse
+// REQUIRES: asserts
+
+// Distributed under the terms of the MIT license
+// Test case submitted to project by https://github.com/practicalswift (practicalswift)
+// Test case found by fuzzing
+
+var _{struct B<a:CollectionType{var _={struct B<a{enum B{case