[clang] [Clang SA]: add support for mismatched ownership_returns+ownership_takes calls for custom allocation classes (PR #98941)

[Balazs Benics via cfe-commits]

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@@ -14,6 +14,13 @@
 void free(void *);
 void __attribute((ownership_takes(malloc, 1))) my_free(void *);
 
+void __attribute((ownership_returns(malloc1))) *my_malloc1(size_t);
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steakhal wrote:

What happens if you have a forward declaration to a malloc function without the attribute, then later have another redeclaration with the `ownership_returns` attribute?
A similar case to test would be the opposite: 1st declaration has the attribute, the second redeclaration would not have the attribute.
I suspect that the FunctionDecl of the callees will refer to the last seen declaration of the function, thus, will not recognize the attribute for the second case I mentioned here.
Could you test these cases?

https://github.com/llvm/llvm-project/pull/98941