Adjust to GCC8 upgrade in Alpine edge

This week (probably today), Alpine is going to upgrade their GCC from version 6 to 8 in Alpine edge. pmOS is based on Alpine edge, hence we need to adjust our aports as well.

I expect breakage in the kernels for example, as older kernels explicitly check for the GCC version and then include a file based on what it found. Newer kernels only include one file if the compiler is GCC, independent of the version.

Here's an issue, so we can note down the progress of the upgrade.