Extension of https://reviews.llvm.org/D141101 to even further reduce the amount of implicit operands we attach. The main benefit is to improve cability of post-ra scheduler, and reduce unneeded dependency resolution (e.g. inserting snops).
Unfortunately, we run into regressions if we completely minimize the amount implicit operands (naively), we run into some regressions (e.g. dual_movs are replaced with multiple calls to v_mov). This is even more reason to switch to LiveRegUnits.
Nonetheless, this patch removes the operands which we can for free (more or less).
Change-Id: Ib4f409202b36bdbc59eed615bc2d19fa8bd8c057
Should do logic on the flags operand and have one addReg call