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

[Kerry McLaughlin via llvm-commits]

================
@@ -50,6 +54,53 @@ TEST(SMEAttributes, Constructors) {
                       ->getFunction("foo"))
                   .preservesZA());
 
+  ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_in\"")
+                      ->getFunction("foo"))
+                  .isZT0In());
+  ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_out\"")
+                      ->getFunction("foo"))
+                  .isZT0Out());
+  ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_inout\"")
+                      ->getFunction("foo"))
+                  .isZT0InOut());
----------------
kmclaughlin-arm wrote:

These are tested a bit further down, on line 93:

```
ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_preserved\"")
                    ->getFunction("foo"))
                .preservesZT0());

ASSERT_TRUE(SA(*parseIR("declare void @foo() \"aarch64_sme_zt0_new\"")
                    ->getFunction("foo"))
                .hasNewZT0Body());
```

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