CPP: Add a test case.

Author: geoffw0

cpp/ql/test/query-tests/Critical/DeadCodeGoto/DeadCodeGoto.expected

@@ -1,3 +1,4 @@
 | test.cpp:2:2:2:12 | goto ... | This statement makes $@ unreachable. | test.cpp:3:2:3:5 | ExprStmt | ExprStmt |
 | test.cpp:9:3:9:8 | break; | This statement makes $@ unreachable. | test.cpp:10:3:10:6 | ExprStmt | ExprStmt |
 | test.cpp:37:3:37:8 | break; | This statement makes $@ unreachable. | test.cpp:38:3:38:11 | return ... | return ... |
+| test.cpp:91:2:91:11 | goto ... | This statement makes $@ unreachable. | test.cpp:93:2:93:5 | ExprStmt | ExprStmt |

cpp/ql/test/query-tests/Critical/DeadCodeGoto/test.cpp

@@ -81,3 +81,29 @@ void test7(int x, int cond) {
 	}
 	end:
 }
+
+#define CONFIG_DEFINE
+
+void test8() {
+	int x = 0;
+
+#ifdef CONFIG_DEFINE
+	goto skip; // GOOD (the `x++` is still reachable in some configurations) [FALSE POSITIVE]
+#endif
+	x++;
+
+skip:
+}
+
+void test9() {
+	int x = 0;
+
+#ifdef CONFIG_NOTDEFINED
+	goto mid;
+#endif
+	goto end; // GOOD (the `x++` is still reachable in some configurations)
+mid:
+	x++;
+
+end:
+}