[clang] [llvm] [AArch64] Merge duplicate extension information. (PR #92319)

[Alexandros Lamprineas via llvm-commits]

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@@ -56,43 +52,64 @@ class Extension<
 
     // The FMV priority
     int FMVPriority = _FMVPriority;
+
+    // Indicates if the extension is available on the command line.
+    string IsFMVOnly = _IsFMVOnly;
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labrinea wrote:

We want the ExtensionInfo field to be of type bool. Can we do the type conversation in the emitter? If so okay

https://github.com/llvm/llvm-project/pull/92319