If somebody want to check it here is trace that from 63180:
https://drive.google.com/file/d/0B5LwC3WbdQ3DUVM2bzMwUlQzSW8
This one have to be opened like that:
MESA_GL_VERSION_OVERRIDE=3.0 qapitrace PA.trace
Then it's will cause GPU lockup on R600g and it's not sun shader, but something
else. Actually it's cause lockup with both default and LLVM shader compiler.

I guess this can be related to how MESA_GL_VERSION_OVERRIDE working. When I run
glxinfo this MESA_GL_VERSION_OVERRIDE=3.0 it's still show that GLSL 3.3
supported so this is why game able to compile shaders at all.

Possible lockup related to invalid (for Mesa) GL call or something else so I
have no idea what this can be.