[llvm] [AArch64][LSR] Prioritize Insns in isLSRCostLess (PR #226525)

[Sander de Smalen via llvm-commits]

sdesmalen-arm wrote:

Perhaps changing the default makes sense overall, but I'd still be a bit cautious to change it as the issue with favouring number of instructions over number of registers is that when the register pressure gets too high, the cost of spills/fills is likely to be more expensive than the extra instructions. Do you have a motivating example where LSR is making the wrong decision based on this?

https://github.com/llvm/llvm-project/pull/226525