**Description:**
As our minifier is two-pass by default, this is enough.
At the first pass, we inline all numeric literals using sequential inliner, and minifier can then inline constants correctly in the second pass.
**Description:**
As we are not using the return value of the function, we can call `ignore_return_value` on the argument of the return statements of IIFE.
**Description:**
This PR renames `CloningMultiReplacer` to `Finalizer` and makes it handle the removal of unused variables. Also, this PR improves the sequential inliner so we can drop variables within a single pass.
**Description:**
We had two passes for joining variables. This PR removes one in the full optimizer, which is wrong.
**Related issue:**
- Closes https://github.com/swc-project/swc/issues/5989.
