JS: Add test showing duplicate alerts

Author: asgerf

javascript/ql/test/query-tests/LanguageFeatures/NonLinearPattern/NonLinearPattern.expected

@@ -2,6 +2,9 @@
 | ts-test.ts:8:16:8:16 | x | Repeated binding of pattern variable 'x' previously bound $@. | ts-test.ts:8:10:8:10 | x | here |
 | ts-test.ts:11:10:11:10 | x | Repeated binding of pattern variable 'x' previously bound $@. | ts-test.ts:11:7:11:7 | x | here |
 | ts-test.ts:21:8:21:13 | string | Repeated binding of pattern variable 'string' previously bound $@. | ts-test.ts:20:8:20:13 | string | here |
+| ts-test.ts:32:16:32:16 | x | Repeated binding of pattern variable 'x' previously bound $@. | ts-test.ts:30:12:30:12 | x | here |
+| ts-test.ts:34:20:34:20 | x | Repeated binding of pattern variable 'x' previously bound $@. | ts-test.ts:30:12:30:12 | x | here |
+| ts-test.ts:34:20:34:20 | x | Repeated binding of pattern variable 'x' previously bound $@. | ts-test.ts:32:16:32:16 | x | here |
 | tst.js:3:13:3:13 | x | Repeated binding of pattern variable 'x' previously bound $@. | tst.js:3:10:3:10 | x | here |
 | tst.js:8:16:8:16 | x | Repeated binding of pattern variable 'x' previously bound $@. | tst.js:8:10:8:10 | x | here |
 | tst.js:11:10:11:10 | x | Repeated binding of pattern variable 'x' previously bound $@. | tst.js:11:7:11:7 | x | here |

javascript/ql/test/query-tests/LanguageFeatures/NonLinearPattern/ts-test.ts

@@ -24,3 +24,15 @@ function f({
 
 function g({x, y}: {x: string, y: string}) { // OK
 }
+
+function blah(arg) {
+    var {
+        x: x,
+        y: {
+            x: x, // NOT OK
+            y: {
+                x: x // NOT OK
+            }
+        }
+    } = arg;
+}