Attempt to fix build error `unknown type name 'uint64_t'`
observed on macOS 10.8 and earlier.

Upstream-Status: Pending
--- server/storage/perfschema/my_thread.h.orig
+++ server/storage/perfschema/my_thread.h
@@ -14,6 +14,8 @@
 #include <pthread_np.h>
 #endif
 
+#include <stdint.h>
+
 #if defined(HAVE_INTEGER_PTHREAD_SELF)
 #include <cstdint>
 #endif