Define 'PyPy_VERSION' to avoid compilation issues.

Author: fangerer

graalpython/com.oracle.graal.python.cext/include/Python.h

@@ -45,6 +45,8 @@
 #define HAVE_FCNTL_H
 #define HAVE_SYS_WAIT_H
 
+#define PYPY_VERSION 0
+
 #include <truffle.h>
 #include <polyglot.h>
 #include <stdio.h>