[llvm] [AArch64][CostModel] Add constraints on which partial reductions are (PR #163728)

[Sushant Gokhale via llvm-commits]

sushgokh wrote:

@david-arm @sdesmalen-arm 
1. Have made cost model change that helps my test
2. Added few more cost model changes and corresponding tests.

https://github.com/llvm/llvm-project/pull/163728