Update Mesa to 17.0.3
- OpenGL 4.5 support for RadeonSI and recent Intel
- Use LLVM 4.0 by default, building with 3.9 is possible via MESA_LLVM_VER
- DRI3 remains enabled at compile time, but is now disabled at runtime for stock FreeBSD. Set LIBGL_DRI3_ENABLE in the environment to enable DRI3. This extra check is added when compiling on stock FreeBSD, not DRM-next. This change was made to work around a problem in libEGL, which fails to fall back to using DRI2 when run on a system without DRI3 support.
Reviewed by: jmd, mat
Approved by: swills (mentor)
Differential Revision: https://reviews.freebsd.org/D10250