New issue by sham1 on void-packages repository

https://github.com/void-linux/void-packages/issues/37349

Description:
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### System

* xuname: `Void 5.15.41_1 i686 GenuineIntel uptodate rFF`
  *output of `xuname` (part of xtools)*
* package: `mesa-21.3.7_1`
  *affected package(s) including the version: `xbps-query -p pkgver <pkgname>`*

### Expected behavior

`llvmpipe` should be enabled for i686 targets. It was excluded from getting `llvmpipe` with the commit 0335439623542f562c56b539d508a922be63c132.

### Actual behavior

`llvmpipe` is not enabled for i686 targets.

### Steps to reproduce the behavior

1. Run something using Mesa with software rendering on i686.