[clang] [llvm] [Clang][AArch64][SVE2p3][SME2p3] Add intrinsics for v9.7a add/add-and-subtract/subtract pairwise operations (PR #187527)

[Kerry McLaughlin via cfe-commits]

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kmclaughlin-arm wrote:

It looks like all three test files are using the same `RUN` lines & macro. Would it be worth squashing them into one `acle_sve2p1_addsubp.c` file?

https://github.com/llvm/llvm-project/pull/187527