[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[Erich Keane via cfe-commits]

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@@ -571,6 +571,9 @@ New features
   if class of allocation and deallocation function mismatches.
   `Documentation <https://clang.llvm.org/docs/analyzer/checkers.html#unix-mismatcheddeallocator-c-c>`__.
 
+- Function effects (the ``nonblocking`` and ``nonallocating`` "performance constraint" attributes)
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erichkeane wrote:

I still want @shafik to review it (as someone who hasn't been mentally 'poisoned' here by knowing too much about the feature), but perhaps his work is greatly reduced.  

https://github.com/llvm/llvm-project/pull/99656