Allow installing Alpine's mesa for x86* arches (currently breaking 'pmbootstrap qemu' for some people)
The mesa version 19.0 added to pmaports.git in pmaports!256 (merged) is needed for arm devices (e.g. it fixes hammerhead blackscreen). But Alpine is currently stuck on 18.2.8 because of x86_64 ATI drivers, which also need a LLVM upgrade (see this PR).
So it would be a good solution to fork the mesa aport for the arm arches, but not for x86*.
This is not supported by pmbootstrap yet:
$ pmbootstrap chroot --add=mesa
[09:47:34] NOTE: You can edit the 'arch=' line inside the APKBUILD
[09:47:34] ERROR: Can't build 'mesa' for architecture x86_64
For people where this causes breakage in qemu, see using QEMU from the host system as workaround.