#605 ppc64 build failure: int32_t

[Jan Engelhardt]

```

if PBYTE_ORDER==PLITTLE_ENDIAN

typedef PIntReversedOrder<int32_t> PInt32b;</int32_t>

elif PBYTE_ORDER==PBIG_ENDIAN

typedef PIntSameOrder<pint32> int32_t;</pint32>

endif

```

This section in ptlib/object.h (ptlib-2.18.8) causes a compile failure on ppc64.
int32_t is a type already reserved by stdint.h and must not be redefined by ptlib.

[Jan Engelhardt]

#if PBYTE_ORDER==PLITTLE_ENDIAN
typedef PIntReversedOrder<int32_t> PInt32b;
#elif PBYTE_ORDER==PBIG_ENDIAN
typedef PIntSameOrder<PInt32> int32_t;
#endif

[Jan Engelhardt]

build-tested only

[Jan Engelhardt]

And this one for opal-3.18.8.