New test for common SourceKit crash

Author: johnno1962

test/SourceKit/CursorInfo/result_test.swift

@@ -0,0 +1,23 @@
+// RUN: %sourcekitd-test -req cursor -pos 17:15 %s -- %s >%t.response
+// RUN: diff -u %s.response %t.response
+
+public protocol MyErrorType {
+}
+
+enum MyErrorEnum: MyErrorType {
+}
+
+public enum ResultTest<Value, Error: MyErrorType> {
+    case Success(Value)
+    case Failure(Error)
+
+    /// Returns `true` if the result is a success, `false` otherwise.
+    public var isSuccess: Bool {
+        switch self {
+        case .Success:
+            return true
+        case .Failure:
+            return false
+        }
+    }
+}

test/SourceKit/CursorInfo/result_test.swift.response

@@ -0,0 +1,17 @@
+source.lang.swift.ref.enumelement (11:10-11:17)
+Success
+s:FO11result_test10ResultTest7Successu0_R_S_11MyErrorTyperFMGS0_xq__FxGS0_xq__
+<Value, Error : MyErrorType> ResultTest<Value, Error>.Type -> (Value) -> ResultTest<Value, Error>
+<Declaration></Declaration>
+OVERRIDES BEGIN
+OVERRIDES END
+RELATED BEGIN
+RELATED END
+TYPE INTERFACE BEGIN
+public enum ResultTest<Value, Error> {
+    case Success(Value)
+    case Failure(Error)
+    /// Returns `true` if the result is a success, `false` otherwise.
+    public var isSuccess: Bool { get }
+}
+TYPE INTERFACE END