[llvm] [AArch64][SME] Lower memchr to __arm_sc_memchr in streaming[-compatible] functions (PR #168896)

[Sam Tebbs via llvm-commits]

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@@ -153,6 +153,160 @@ entry:
   ret void
 }
 
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SamTebbs33 wrote:

Is there a memchr test for when streaming mode and streaming compatible mode are not enabled?

https://github.com/llvm/llvm-project/pull/168896