C#: Add test showing false positive

Author: calumgrant

csharp/ql/test/query-tests/Likely Bugs/DangerousNonShortCircuitLogic/DangerousNonShortCircuitLogic.cs

@@ -20,6 +20,8 @@ void M()
         var b = true;
         b &= c.Method(); // GOOD
         b |= c[0]; // GOOD
+
+        if (c == null | c.Method(out _)) ; // GOOD (false positive)
     }
 
     class C
@@ -28,6 +30,7 @@ class C
         public string Property { get; set; }
         public bool this[int i] { get { return false; } set { } }
         public bool Method() { return false; }
+        public bool Method(out int x) { x = 0; return false; }
     }
 }
 

csharp/ql/test/query-tests/Likely Bugs/DangerousNonShortCircuitLogic/DangerousNonShortCircuitLogic.expected

@@ -2,3 +2,4 @@
 | DangerousNonShortCircuitLogic.cs:16:13:16:40 | ... \| ... | Potentially dangerous use of non-short circuit logic. |
 | DangerousNonShortCircuitLogic.cs:17:13:17:28 | ... \| ... | Potentially dangerous use of non-short circuit logic. |
 | DangerousNonShortCircuitLogic.cs:18:13:18:34 | ... \| ... | Potentially dangerous use of non-short circuit logic. |
+| DangerousNonShortCircuitLogic.cs:24:13:24:39 | ... \| ... | Potentially dangerous use of non-short circuit logic. |