[llvm] [MC][DWARF][NFC] Drop CIEKey map (PR #96075)

[Fangrui Song via llvm-commits]

================
@@ -1819,44 +1803,28 @@ struct CIEKey {
                            Other.IsMTETaggedFrame);
   }
 
-  const MCSymbol *Personality;
-  unsigned PersonalityEncoding;
-  unsigned LsdaEncoding;
-  bool IsSignalFrame;
-  bool IsSimple;
-  unsigned RAReg;
-  bool IsBKeyFrame;
-  bool IsMTETaggedFrame;
+  bool operator==(const CIEKey &Other) const {
+    return Personality == Other.Personality &&
+           PersonalityEncoding == Other.PersonalityEncoding &&
+           LsdaEncoding == Other.LsdaEncoding &&
+           IsSignalFrame == Other.IsSignalFrame && IsSimple == Other.IsSimple &&
+           RAReg == Other.RAReg && IsBKeyFrame == Other.IsBKeyFrame &&
+           IsMTETaggedFrame == Other.IsMTETaggedFrame;
+  }
+  bool operator!=(const CIEKey &Other) const { return !(*this == Other); }
+
+  const MCSymbol *Personality = nullptr;
+  unsigned PersonalityEncoding = 0;
+  unsigned LsdaEncoding = -1;
+  bool IsSignalFrame = false;
+  bool IsSimple = false;
+  unsigned RAReg = static_cast<unsigned>(INT_MAX);
----------------
MaskRay wrote:

Why INT_MAX instead of UINT_MAX?

https://github.com/llvm/llvm-project/pull/96075