Make some number configure macros public in non-limited capi

Some non-standard macros in pyconfig.h (like SIZEOF_VOID_P or LONG_BIT) are useful (for example, numpy use them). This idea is to make them public: In pyconfig.h.in, change it to _Py_* In Python.h add the code like it to avoid the breaking-forward for normal build: #ifndef Py_LIMITED_API #ifdef _Py_SIZEOF_VOID_P #define Py_SIZEOF_VOID_P _Py_SIZEOF_VOID_P #endif // and any other number macros #endif