[clang] [clang][StaticAnalyzer] Adding getentropy to CStringChecker. (PR #83675)

[Balazs Benics via cfe-commits]

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@@ -529,3 +529,42 @@ void nocrash_on_locint_offset(void *addr, void* from, struct S s) {
   size_t iAdd = (size_t) addr;
   memcpy(((void *) &(s.f)), from, iAdd);
 }
+
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+/* present in both glibc 2.25 and musl 1.1.20 */
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steakhal wrote:

We add the declaration in the test, so I don't think we should conditionally include this test.
```suggestion
```

https://github.com/llvm/llvm-project/pull/83675