jscript: Throw proper error when calling Set constructor as method.

dlls/jscript/set.c

@@ -572,6 +572,9 @@ static HRESULT Set_constructor(script_ctx_t *ctx, jsval_t vthis, WORD flags, uns
         *r = jsval_obj(&set->dispex);
         return S_OK;
 
+    case DISPATCH_METHOD:
+        return throw_error(ctx, JS_E_WRONG_THIS, L"Set");
+
     default:
         FIXME("unimplemented flags %x\n", flags);
         return E_NOTIMPL;

dlls/mshtml/tests/documentmode.js

@@ -1201,6 +1201,13 @@ sync_test("func_scope", function() {
 sync_test("set_obj", function() {
     if(!("Set" in window)) return;
 
+    try {
+        var s = Set();
+        ok(false, "expected exception calling constructor as method");
+    }catch(e) {
+        ok(e.number === 0xa13fc - 0x80000000, "calling constructor as method threw " + e.number);
+    }
+
     var s = new Set, r;
     ok(Object.getPrototypeOf(s) === Set.prototype, "unexpected Set prototype");