[compiler-rt] [rtsan] Add include guards around posix interceptors, tests (PR #113188)

[Chris Apple via llvm-commits]

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@@ -8,12 +8,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "sanitizer_common/sanitizer_platform.h"
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cjappl wrote:

It is what defines SANITIZER_POSIX

https://github.com/llvm/llvm-project/pull/113188