This is an adoption of #12670 plus some documentation fixes. See that PR
for more details.
---
## Changelog
* Renamed `BufferVec` to `RawBufferVec` and added a new `BufferVec`
type.
## Migration Guide
`BufferVec` has been renamed to `RawBufferVec` and a new similar type
has taken the `BufferVec` name.
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Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>