Add a test of an odd pattern that shows up in Angular.

One of my upcoming CLs currently produces an error for this pattern, so having this test in place will make it easier to fix that CL.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=143497109

test/com/google/javascript/jscomp/VariableReferenceCheckTest.java

@@ -53,6 +53,25 @@ public void setUp() throws Exception {
     enableUnusedLocalAssignmentCheck = false;
   }
 
+  public void testDoubleTryCatch() {
+    testSame(
+        LINE_JOINER.join(
+            "function g() {",
+            "  return f;",
+            "",
+            "  function f() {",
+            "    try {",
+            "    } catch (e) {",
+            "      alert(e);",
+            "    }",
+            "    try {",
+            "    } catch (e) {",
+            "      alert(e);",
+            "    }",
+            "  }",
+            "}"));
+  }
+
   public void testCorrectCode() {
     assertNoWarning("function foo(d) { (function() { d.foo(); }); d.bar(); } ");
     assertNoWarning("function foo() { bar(); } function bar() { foo(); } ");