intel/ir: Remove scheduling-based cycle count estimates.
The cycle count estimation logic part of the scheduler is now redundant with the shader performance modeling pass, and the estimates can be consolidated into the brw::performance analysis result object instead of being part of the CFG, which guarantees that the estimates cannot be accessed without previously calling the performance_analysis::require() method, which makes sure that the right analysis pass is executed at the right time if we don't already have up-to-date cached results. Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>