Java: add flexible constructor test including CFG predecessor query

Author: IdrissRio

java/ql/test/library-tests/flexible-constructors/SuperPredecessor.expected

@@ -0,0 +1,6 @@
+| FlexibleConstructors.java:10:15:10:17 | msg | FlexibleConstructors.java:10:9:10:19 | super(...) | predecessor of explicit super() |
+| FlexibleConstructors.java:18:13:18:17 | ... < ... | FlexibleConstructors.java:19:9:19:16 | super(...) | predecessor of explicit super() |
+| FlexibleConstructors.java:38:17:38:48 | combined | FlexibleConstructors.java:39:13:39:20 | super(...) | predecessor of explicit super() |
+| FlexibleConstructors.java:52:9:52:40 | ...=... | FlexibleConstructors.java:53:9:53:16 | super(...) | predecessor of explicit super() |
+| FlexibleConstructors.java:65:15:65:18 | temp | FlexibleConstructors.java:65:9:65:20 | super(...) | predecessor of explicit super() |
+| FlexibleConstructors.java:77:9:77:24 | ...=... | FlexibleConstructors.java:78:9:78:16 | super(...) | predecessor of explicit super() |

java/ql/test/library-tests/flexible-constructors/SuperPredecessor.ql

@@ -0,0 +1,11 @@
+import java
+
+from ControlFlowNode pred, ControlFlowNode supNode, SuperConstructorInvocationStmt sc
+where
+  supNode.asStmt() = sc and
+  pred.getASuccessor() = supNode and
+  pred != supNode and
+  not pred.asStmt() instanceof BlockStmt and
+  exists( sc.getEnclosingCallable().getFile().getRelativePath() ) and
+  sc.getLocation().getEndColumn() > sc.getLocation().getStartColumn()
+select pred, sc, "predecessor of explicit super()"