[llvm] [AArch64][SME2] Add ZT0 attributes to SMEAttrs (PR #77607)

[Kerry McLaughlin via llvm-commits]

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@@ -50,6 +54,22 @@ TEST(SMEAttributes, Constructors) {
                       ->getFunction("foo"))
                   .preservesZA());
 
+  ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_in\"")
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kmclaughlin-arm wrote:

I've changed the attributes to use this format, I think this makes sense given the Clang attribute will be `__arm_in("zt0")`

https://github.com/llvm/llvm-project/pull/77607