Changes
### Added
- Class constant initializers and class/trait property defaults accept a full expression instead of a single literal, so `const INT8_MIN = -0x7f - 1;`, `const MASK = 0xff << 8 | 0x0f;` and `public size = 1024 * 8 { get };` now parse. Both positions reuse the ordinary expression non-terminal, so the default node is a regular expression node (`sub`, `bitwise_or`, `ternary`, ...) and every form that already parsed keeps its exact node shape. The grammar deliberately accepts more than a constant expression; the compiler folds the node and names the sub-expression it cannot resolve ([zephir-lang/zephir#2061](https://github.com/zephir-lang/zephir/issues/2061)).