LibJS: Allow binding patterns as for in/of targets

Userland/Libraries/LibJS/Parser.cpp

@@ -1701,7 +1701,7 @@ NonnullRefPtr<VariableDeclaration> Parser::parse_variable_declaration(bool for_l
             init = parse_expression(2);
         } else if (!for_loop_variable_declaration && declaration_kind == DeclarationKind::Const) {
             syntax_error("Missing initializer in 'const' variable declaration");
-        } else if (target.has<NonnullRefPtr<BindingPattern>>()) {
+        } else if (!for_loop_variable_declaration && target.has<NonnullRefPtr<BindingPattern>>()) {
             syntax_error("Missing initializer in destructuring assignment");
         }
 

Userland/Libraries/LibJS/Tests/loops/for-in-basic.js

@@ -49,3 +49,7 @@ test("use already-declared variable", () => {
     for (property in "abc");
     expect(property).toBe("2");
 });
+
+test("allow binding patterns", () => {
+    expect(`for (let [a, b] in foo) {}`).toEval();
+});

Userland/Libraries/LibJS/Tests/loops/for-of-basic.js

@@ -98,3 +98,7 @@ describe("errors", () => {
         }).toThrowWithMessage(TypeError, "[object Object] is not iterable");
     });
 });
+
+test("allow binding patterns", () => {
+    expect(`for (let [a, b] of foo) {}`).toEval();
+});