Another “improvement” is that now blender 2.81 works decently on Linux, on a whole generation of radeon HD, 10 years of GPU from 2006 to 2016
I found a workaround by activating strings for Mesa opensource drivers
I tested a radeon HD 7670m and a radeon HD 2600 XT 512 mb ram. from 2007!
I made a video showing the performances (obviously related to these old GPUs) and wrote the instructions here.