LibJS: Fix returning from try statement

Not sure if this regressed at some point or just never worked, it
definitely wasn't tested at all. We would always return undefined when
returning from a try statement block, handler, or finalizer.

Userland/Libraries/LibJS/Tests/try-catch-finally-return.js

@@ -0,0 +1,34 @@
+test("return from try block", () => {
+    function foo() {
+        try {
+            return "foo";
+        } catch {
+            return "bar";
+        }
+    }
+    expect(foo()).toBe("foo");
+});
+
+test("return from catch block", () => {
+    function foo() {
+        try {
+            throw "foo";
+        } catch {
+            return "bar";
+        }
+    }
+    expect(foo()).toBe("bar");
+});
+
+test("return from finally block", () => {
+    function foo() {
+        try {
+            return "foo";
+        } catch {
+            return "bar";
+        } finally {
+            return "baz";
+        }
+    }
+    expect(foo()).toBe("baz");
+});