JavaScript: Add more statements to test cases for `DuplicateToplevel`.

Now both `a.js` and `b.js` have ten (non-block) statements, which allows for more interesting tests.

javascript/ql/test/query-tests/external/DuplicateToplevel/a.js

@@ -7,4 +7,7 @@
 	arguments[0]--;
 	arguments[1] += 19;
 	arguments[0] * arguments[1];
+	arguments[2] / arguments[3];
+	arguments[4] % arguments[5];
+	arguments[6] % arguments[7];
 }

javascript/ql/test/query-tests/external/DuplicateToplevel/b.js

@@ -7,4 +7,7 @@
 	arguments[0]--;
 	arguments[1] += 19;
 	arguments[0] * arguments[1];
+	arguments[2] / arguments[3];
+	arguments[4] % arguments[5];
+	arguments[6] % arguments[7];
 }