JS: add test case

Author: asger-semmle

javascript/ql/test/library-tests/RangeAnalysis/expressions.js

@@ -0,0 +1,9 @@
+function f(arr) {
+  if (arr.length > 2) {} // OK
+  
+  let x = arr.length || 0;
+  if (x > 2) {} // OK
+  
+  let y = arr.length && 3;
+  if (y > 2) {} // OK
+}