[clang] Add check in SemaChecking for multiple unsequenced volatile accesses (PR #180955)

[Shafik Yaghmour via cfe-commits]

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@@ -14034,6 +14034,8 @@ class SequenceChecker : public ConstEvaluatedExprVisitor<SequenceChecker> {
     UK_Count = UK_ModAsSideEffect + 1
   };
 
+  enum WarningKind { WK_UseAndMod, WK_ModAndMod, WK_Volatile_UseAndUse };
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shafik wrote:

This should be documented with the same care as `UsageKind` above.

https://github.com/llvm/llvm-project/pull/180955