[llvm] [AArch64][CodeGen] Add patterns for +lsfe atomic stores (PR #131174)

[Kerry McLaughlin via llvm-commits]

kmclaughlin-arm wrote:

@tmatheson-arm @davemgreen I've moved the tests & changes to the generate-tests script into https://github.com/llvm/llvm-project/pull/132022, adding a reference to this PR.

https://github.com/llvm/llvm-project/pull/131174