This patch optimises the Metal inlining policy. It gives a small speedup (2-3% on M1 Max) with no notable compilation slowdown vs what is already in master. Previously noted compilation slowdowns (as reported in T100102) were caused by forcing inlining for `ccl_device`, but we get better rendering perf by relying on compiler heuristics in these cases. Reviewed By: brecht Differential Revision: https://developer.blender.org/D16081