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

[Sander de Smalen via llvm-commits]

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@@ -58,6 +78,39 @@ TEST(SMEAttributes, Constructors) {
   EXPECT_DEBUG_DEATH(SA(SA::ZA_New | SA::ZA_Preserved),
                      "ZA_New and ZA_Preserved are mutually exclusive");
 
+  EXPECT_DEBUG_DEATH(SA(SA::ZT0_New | SA::ZT0_In),
+                     "ZT0_New, ZT0_In, ZT0_Out, ZT0_InOut and ZT0_Preserved "
+                     "are all \" \"mutually exclusive");
+  EXPECT_DEBUG_DEATH(SA(SA::ZT0_New | SA::ZT0_Out),
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sdesmalen-arm wrote:

If you'd implement my suggestion above, there is no longer a need for these tests here.
But I would argue that we'd need some checks in Verifier.cpp for these attributes, which would be more user-facing.

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