[clang] [PAC][clang] Define `PointerAuthQualifier` and `PointerAuthenticationMode` (PR #84384)

[Daniil Kovalev via cfe-commits]

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@@ -251,15 +423,16 @@ class Qualifiers {
   }
 
   // Deserialize qualifiers from an opaque representation.
-  static Qualifiers fromOpaqueValue(unsigned opaque) {
+  static Qualifiers fromOpaqueValue(uint64_t Opaque) {
     Qualifiers Qs;
-    Qs.Mask = opaque;
+    Qs.Mask = uint32_t(Opaque);
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kovdan01 wrote:

Is this OK or should we prefer smth like `Opaque & 0xFFFFFFFF` or even `Opaque & std::numeric_limits<uint32_t>::max()` (or smth else)?


https://github.com/llvm/llvm-project/pull/84384