Yesterday after compiling mesa with your commit, all was working fine on the
lowest setting, but it was still crashing with cockpit view on replay with low
setting.

This morning i made another mesa compilation because it was missing
--enable-debug and now the game stop at launch screen with:

error at : SETGE_INT     R7.x.2F@R124.y,    R6.z.2||FP@R3.z,
4.2039e-45|00000003
  : operand value R6.z.2||FP@R3.z was not previously written to its gpr
error at : ADD_INT     R27.x.2||FP@R2.x,    R6.z.2||FP@R3.z,
4.2039e-45|00000003
  : operand value R6.z.2||FP@R3.z was not previously written to its gpr
error at : (copy) MOV     t20||FP@R4.x,    R6.z.2||FP@R3.z
  : operand value R6.z.2||FP@R3.z was not previously written to its gpr
sb/sb_ra_checker.cpp:46:run: Assertion `sh.errors.empty()' failed.
/media/sdc2/SteamLibrary/SteamApps/common/GRID Autosport/GridAutosport.sh :
ligne 19 : 31901 Trappe pour point d'arrêt et de trace              (core
dumped)"${GAMEROOT}/bin/GridAutosport" $@

There is 5 new commit since yours and one have modification on shaders so maybe
it's related.