CPP: More thorough test of LambdaCapture.

Author: geoffw0

cpp/ql/test/library-tests/lambdas/captures/captures.expected

@@ -1,6 +1,6 @@
-| captures.cpp:3:6:3:6 | x | explicit | 0 |
-| captures.cpp:3:9:3:12 | (captured this) | explicit | 1 |
-| captures.cpp:10:7:10:7 | (captured this) | implicit | 0 |
-| captures.cpp:10:9:10:9 | x | implicit | 1 |
-| captures.cpp:15:6:15:6 | x | explicit | 0 |
-| end_pos.cpp:9:17:9:18 | ii | explicit | 0 |
+| captures.cpp:3:6:3:6 | x | explicit | 0 | x | x |
+| captures.cpp:3:9:3:12 | (captured this) | explicit | 1 | (captured this) | this |
+| captures.cpp:10:7:10:7 | (captured this) | implicit | 0 | (captured this) | this |
+| captures.cpp:10:9:10:9 | x | implicit | 1 | x | x |
+| captures.cpp:15:6:15:6 | x | explicit | 0 | x | x |
+| end_pos.cpp:9:17:9:18 | ii | explicit | 0 | ii | ii |

cpp/ql/test/library-tests/lambdas/captures/captures.ql

@@ -4,4 +4,4 @@ from LambdaCapture lc, string mode, int index
 where
   exists(LambdaExpression le | le.getCapture(index) = lc) and
   if lc.isImplicit() then mode = "implicit" else mode = "explicit"
-select lc, mode, index
+select lc, mode, index, concat(lc.getField().toString(), ", "), concat(lc.getInitializer().toString(), ", ")