MariaRocks: attempt to get to compile on Windows

\include\mysql/psi/psi.h(1267): error C2061: syntax error:
identifier 'pthread_t' (compiling source file D:\win32-debug\build\src
\storage\rocksdb\rdb_psi.cc)\include\mysql/psi/psi.h(1267):
error C2061: syntax error: identifier 'pthread_t' (compiling source
file D:\win32-debug\build\src\storage\rocksdb\rdb_psi.cc)

storage/rocksdb/rdb_psi.h

@@ -19,6 +19,7 @@
 
 /* MySQL header files */
 #include <my_global.h>
+#include <my_pthread.h>
 #include <mysql/psi/psi.h>
 
 /* MyRocks header files */