Added tests for arrays toSpliced with pop

Author: Napalys

javascript/ql/test/library-tests/Arrays/arrays.js

@@ -94,4 +94,17 @@
 
   sink(["source"].filter((x) => x)); // NOT OK
   sink(["source"].filter((x) => !!x)); // NOT OK
+  
+  var arr8 = [];
+  arr8 = arr8.toSpliced(0, 0, "source");
+  sink(arr8.pop()); // NOT OK -- Should be considered tainted, but it is not
+
+  var arr8_variant = [];
+  arr8_variant = arr8_variant.toSpliced(0, 0, "safe", "source");
+  arr8_variant.pop();
+  sink(arr8_variant.pop()); // NOT OK -- Should be considered tainted, but it is not
+
+  var arr8_spread = [];
+  arr8_spread = arr8_spread.toSpliced(0, 0, ...arr);
+  sink(arr8_spread.pop()); // NOT OK -- Should be considered tainted, but it is not
 });