Add regression test for fixed crasher

Author: slavapestov

validation-test/compiler_crashers_2_fixed/rdar144302927.swift

@@ -0,0 +1,14 @@
+// RUN: %target-typecheck-verify-swift
+
+protocol P {
+  typealias A = () -> Void
+  func f(_: Int) -> (Int, A)
+  // expected-note@-1 {{protocol requires function 'f' with type '(Int) -> (Int, Self.A)' (aka '(Int) -> (Int, () -> ())')}}
+}
+
+class C: P {
+  // expected-error@-1 {{type 'C' does not conform to protocol 'P'}}
+  // expected-note@-2 {{add stubs for conformance}}
+  func f(_: Int) -> Int { fatalError() }
+  // expected-note@-1 {{candidate has non-matching type '(Int) -> Int'}}
+}