[clang] Thread Safety Analysis: Support reentrant capabilities (PR #137133)

[Aaron Ballman via cfe-commits]

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@@ -3990,6 +3990,13 @@ def LocksExcluded : InheritableAttr {
   let Documentation = [Undocumented];
 }
 
+def ReentrantCapability : InheritableAttr {
+  let Spellings = [Clang<"reentrant_capability">];
+  let Subjects = SubjectList<[Record, TypedefName]>;
+  let Documentation = [Undocumented];
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AaronBallman wrote:

We generally don't want new, undocumented attributes. However, I think this is fine because we have dedicated documentation for this elsewhere which is being updated, and this matches the same lack of documentation as the rest of the thread safety attributes.

https://github.com/llvm/llvm-project/pull/137133