[llvm] [clang] [RISCV][MC] Add experimental support of Zaamo and Zalrsc (PR #78970)

[Craig Topper via cfe-commits]

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@@ -168,6 +168,18 @@ def FeatureStdExtZa64rs : SubtargetFeature<"za64rs", "HasStdExtZa64rs", "true",
 def FeatureStdExtZa128rs : SubtargetFeature<"za128rs", "HasStdExtZa128rs", "true",
                                             "'Za128rs' (Reservation Set Size of at Most 128 Bytes)">;
 
+def FeatureStdExtZaamo
+    : SubtargetFeature<"experimental-zaamo", "HasStdExtZaamo", "true",
+                       "'Zaamo' (Atomic Memory Operations)">;
+def HasStdExtZaamo : Predicate<"Subtarget->hasStdExtZaamo()">,
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topperc wrote:

This predicate isn't used

https://github.com/llvm/llvm-project/pull/78970