JS: Add: taint step for Object.groupBy function, fixed test cases from 8ae05d8be4

javascript/ql/lib/semmle/javascript/Collections.qll

@@ -158,7 +158,7 @@ private module CollectionDataFlow {
   private class GroupByTaintStep extends TaintTracking::SharedTaintStep {
     override predicate heapStep(DataFlow::Node pred, DataFlow::Node succ) {
       exists(DataFlow::MethodCallNode call |
-        call = DataFlow::globalVarRef("Map").getAMemberCall("groupBy") and
+        call = DataFlow::globalVarRef(["Map", "Object"]).getAMemberCall("groupBy") and
         pred = call.getArgument(0) and
         succ = call
       )

javascript/ql/test/library-tests/TaintTracking/BasicTaintTracking.expected

@@ -245,6 +245,7 @@ typeInferenceMismatch
 | tst.js:2:13:2:20 | source() | tst.js:68:10:68:23 | x.toReversed() |
 | tst.js:2:13:2:20 | source() | tst.js:70:10:70:18 | xReversed |
 | tst.js:2:13:2:20 | source() | tst.js:72:10:72:31 | Map.gro ... z => z) |
+| tst.js:2:13:2:20 | source() | tst.js:74:10:74:34 | Object. ... z => z) |
 | xml.js:5:18:5:25 | source() | xml.js:8:14:8:17 | text |
 | xml.js:12:17:12:24 | source() | xml.js:13:14:13:19 | result |
 | xml.js:23:18:23:25 | source() | xml.js:20:14:20:17 | attr |

javascript/ql/test/library-tests/TaintTracking/tst.js

@@ -71,5 +71,5 @@ function test() {
 
     sink(Map.groupBy(x, z => z)); // NOT OK
     sink(Custom.groupBy(x, z => z)); // OK
-    sink(Object.groupBy(x, z => z)); // NOT OK -- This should be marked via taint step, but it is not.
+    sink(Object.groupBy(x, z => z)); // NOT OK
 }