bpo-35059: Add Py_STATIC_INLINE() macro (GH-10093)
- Add Py_STATIC_INLINE() macro to declare a "static inline" function. If the compiler supports it, try to always inline the function even if no optimization level was specified.
- Modify pydtrace.h to use Py_STATIC_INLINE() when WITH_DTRACE is not defined.
- Add an unit test on Py_DECREF() to make sure that _Py_NegativeRefcount() reports the correct filename.