Introduce JS_DefineProperties, DRY error handling

[bnoordhuis]

We should consider introducing a JS_DefineProperties or something like it that sets properties in bulk, to make it easier to handle errors, and port code in quickjs.c over to it.

Case in point: js_regexp_exec dedicates 100 lines to setting properties on the result object. Here's an excerpt:

        t = groups, groups = JS_UNDEFINED;
        if (JS_DefinePropertyValue(ctx, obj, JS_ATOM_groups,
                                   t, prop_flags) < 0) {
            goto fail;
        }

        t = js_int32((capture[0] - str_buf) >> shift);
        if (JS_DefinePropertyValue(ctx, obj, JS_ATOM_index, t, prop_flags) < 0)
            goto fail;

        t = str_val, str_val = JS_UNDEFINED;
        if (JS_DefinePropertyValue(ctx, obj, JS_ATOM_input, t, prop_flags) < 0)
            goto fail;

        if (!JS_IsUndefined(indices)) {
            t = indices_groups, indices_groups = JS_UNDEFINED;
            if (JS_DefinePropertyValue(ctx, indices, JS_ATOM_groups,
                                       t, prop_flags) < 0) {
                goto fail;
            }
            t = indices, indices = JS_UNDEFINED;
            if (JS_DefinePropertyValue(ctx, obj, JS_ATOM_indices,
                                       t, prop_flags) < 0) {
                goto fail;
            }
        }

For the record: JS_SetPropertyFunctionList and JS_NewObjectFrom exist and sort of cover this use case, although not exactly.