Sync files.

csharp/ql/lib/semmle/code/csharp/dataflow/internal/FlowSummaryImpl.qll

@@ -1050,6 +1050,16 @@ module Private {
       not exists(interpretComponent(c))
     }
 
+    /**
+     * Holds if token `part` of specification `spec` has an invalid index.
+     * E.g., `Argument[-1]`.
+     */
+    predicate invalidIndexComponent(AccessPath spec, AccessPathToken part) {
+      part = spec.getToken(_) and
+      part.getName() = ["Parameter", "Argument"] and
+      AccessPath::parseInt(part.getArgumentList()) < 0
+    }
+
     private predicate inputNeedsReference(AccessPathToken c) {
       c.getName() = "Argument" or
       inputNeedsReferenceSpecific(c)