[llvm] [AArch64][SDAG] Enable +sme2p2/+sve2p2 lowering for compressstore (PR #218624)

[Jack Styles via llvm-commits]

Stylie777 wrote:

@sdesmalen-arm @MacDue I've just pushed https://github.com/llvm/llvm-project/pull/218624/changes/8c824d4675bfc1aa37ecaf127e1978d405b66b71 to allow i8i16 types in Streaming mode as I realised these were not working on checking the cost model tests. 

https://github.com/llvm/llvm-project/pull/218624