**Description:**
This PR is to prepare removal of `string-cache`. Actually, this PR does not remove it. Instead, this PR only removes direct usages of `js_word!`s, especially in patterns.
**Related issue:**
- #4946.
**Description:**
We should apply `regenerator` after `block_scoping` because `regenerator` does not know how to handle `const`s.
**Related issue:**
- Closes https://github.com/swc-project/swc/issues/3006