LibJS: Add a basic test for the "throw" keyword

Libraries/LibJS/Tests/throw-basic.js

@@ -0,0 +1,26 @@
+function assert(x) { if (!x) console.log("FAIL"); }
+
+try {
+    throw 1;
+} catch (e) {
+    assert(e === 1);
+}
+
+try {
+    throw [99];
+} catch (e) {
+    assert(typeof e === "object");
+    assert(e.length === 1);
+}
+
+function foo() {
+    throw "hello";
+}
+
+try {
+    foo();
+} catch (e) {
+    assert(e === "hello");
+}
+
+console.log("PASS");