Provide mpers_ptr_t definition for non-mpers case

In mpers case, mpers_ptr_t is already defined by DEF_MPERS_TYPE(...).
This allows use of mpers_ptr_t regardless of IN_MPERS state.

* mpers_type.h [!IN_MPERS] (mpers_ptr_t): New typedef.

mpers_type.h

@@ -49,6 +49,7 @@
 # else
 #  define MPERS_DEFS "native_defs.h"
 # endif
+typedef unsigned long mpers_ptr_t;
 #endif
 
 #endif /* !STRACE_MPERS_TYPE_H */