C++: Add upgrade and downgrade script

Author: jketema

cpp/downgrades/cf72c8898d19eb1b3374432cf79d8276cb07ad43/exprparents.ql

@@ -0,0 +1,21 @@
+class Element extends @element {
+  string toString() { none() }
+}
+
+class Expr extends @expr {
+  string toString() { none() }
+}
+
+class Stmt extends @stmt {
+  string toString() { none() }
+}
+
+predicate isStmtWithInitializer(Stmt stmt) {
+  exists(int kind | stmts(stmt, kind, _) | kind = 2 or kind = 11 or kind = 35)
+}
+
+from Expr child, int index, int index_new, Element parent
+where
+  exprparents(child, index, parent) and
+  if isStmtWithInitializer(parent) then index_new = index - 1 else index_new = index
+select child, index_new, parent