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.
diff --git a/Include/object.h b/Include/object.h
index c0371c8..8b2afc2 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -729,8 +729,8 @@
  */
 #ifdef Py_REF_DEBUG
 PyAPI_DATA(Py_ssize_t) _Py_RefTotal;
-PyAPI_FUNC(void) _Py_NegativeRefcount(const char *fname,
-                                            int lineno, PyObject *op);
+PyAPI_FUNC(void) _Py_NegativeRefcount(const char *filename, int lineno,
+                                      PyObject *op);
 PyAPI_FUNC(Py_ssize_t) _Py_GetRefTotal(void);
 #define _Py_INC_REFTOTAL        _Py_RefTotal++
 #define _Py_DEC_REFTOTAL        _Py_RefTotal--
diff --git a/Include/pydtrace.h b/Include/pydtrace.h
index 037961d..cfe192f 100644
--- a/Include/pydtrace.h
+++ b/Include/pydtrace.h
@@ -25,29 +25,29 @@
 
 /* Without DTrace, compile to nothing. */
 
-static inline void PyDTrace_LINE(const char *arg0, const char *arg1, int arg2) {}
-static inline void PyDTrace_FUNCTION_ENTRY(const char *arg0, const char *arg1, int arg2)  {}
-static inline void PyDTrace_FUNCTION_RETURN(const char *arg0, const char *arg1, int arg2) {}
-static inline void PyDTrace_GC_START(int arg0) {}
-static inline void PyDTrace_GC_DONE(int arg0) {}
-static inline void PyDTrace_INSTANCE_NEW_START(int arg0) {}
-static inline void PyDTrace_INSTANCE_NEW_DONE(int arg0) {}
-static inline void PyDTrace_INSTANCE_DELETE_START(int arg0) {}
-static inline void PyDTrace_INSTANCE_DELETE_DONE(int arg0) {}
-static inline void PyDTrace_IMPORT_FIND_LOAD_START(const char *arg0) {}
-static inline void PyDTrace_IMPORT_FIND_LOAD_DONE(const char *arg0, int arg1) {}
+Py_STATIC_INLINE(void) PyDTrace_LINE(const char *arg0, const char *arg1, int arg2) {}
+Py_STATIC_INLINE(void) PyDTrace_FUNCTION_ENTRY(const char *arg0, const char *arg1, int arg2)  {}
+Py_STATIC_INLINE(void) PyDTrace_FUNCTION_RETURN(const char *arg0, const char *arg1, int arg2) {}
+Py_STATIC_INLINE(void) PyDTrace_GC_START(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_GC_DONE(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_INSTANCE_NEW_START(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_INSTANCE_NEW_DONE(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_INSTANCE_DELETE_START(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_INSTANCE_DELETE_DONE(int arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_IMPORT_FIND_LOAD_START(const char *arg0) {}
+Py_STATIC_INLINE(void) PyDTrace_IMPORT_FIND_LOAD_DONE(const char *arg0, int arg1) {}
 
-static inline int PyDTrace_LINE_ENABLED(void) { return 0; }
-static inline int PyDTrace_FUNCTION_ENTRY_ENABLED(void) { return 0; }
-static inline int PyDTrace_FUNCTION_RETURN_ENABLED(void) { return 0; }
-static inline int PyDTrace_GC_START_ENABLED(void) { return 0; }
-static inline int PyDTrace_GC_DONE_ENABLED(void) { return 0; }
-static inline int PyDTrace_INSTANCE_NEW_START_ENABLED(void) { return 0; }
-static inline int PyDTrace_INSTANCE_NEW_DONE_ENABLED(void) { return 0; }
-static inline int PyDTrace_INSTANCE_DELETE_START_ENABLED(void) { return 0; }
-static inline int PyDTrace_INSTANCE_DELETE_DONE_ENABLED(void) { return 0; }
-static inline int PyDTrace_IMPORT_FIND_LOAD_START_ENABLED(void) { return 0; }
-static inline int PyDTrace_IMPORT_FIND_LOAD_DONE_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_LINE_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_FUNCTION_ENTRY_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_FUNCTION_RETURN_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_GC_START_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_GC_DONE_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_INSTANCE_NEW_START_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_INSTANCE_NEW_DONE_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_INSTANCE_DELETE_START_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_INSTANCE_DELETE_DONE_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_IMPORT_FIND_LOAD_START_ENABLED(void) { return 0; }
+Py_STATIC_INLINE(int) PyDTrace_IMPORT_FIND_LOAD_DONE_ENABLED(void) { return 0; }
 
 #endif /* !WITH_DTRACE */
 
diff --git a/Include/pyport.h b/Include/pyport.h
index f4b547a..2f87f53 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -164,20 +164,37 @@
  */
 
 #if defined(_MSC_VER)
-#if defined(PY_LOCAL_AGGRESSIVE)
-/* enable more aggressive optimization for visual studio */
-#pragma optimize("agtw", on)
+#  if defined(PY_LOCAL_AGGRESSIVE)
+   /* enable more aggressive optimization for visual studio */
+#  pragma optimize("agtw", on)
 #endif
-/* ignore warnings if the compiler decides not to inline a function */
-#pragma warning(disable: 4710)
-/* fastest possible local call under MSVC */
-#define Py_LOCAL(type) static type __fastcall
-#define Py_LOCAL_INLINE(type) static __inline type __fastcall
+   /* ignore warnings if the compiler decides not to inline a function */
+#  pragma warning(disable: 4710)
+   /* fastest possible local call under MSVC */
+#  define Py_LOCAL(type) static type __fastcall
+#  define Py_LOCAL_INLINE(type) static __inline type __fastcall
 #else
-#define Py_LOCAL(type) static type
-#define Py_LOCAL_INLINE(type) static inline type
+#  define Py_LOCAL(type) static type
+#  define Py_LOCAL_INLINE(type) static inline type
 #endif
 
+/* Declare a "static inline" function. Typical usage:
+
+     Py_STATIC_INLINE(int) add(int a, int b) { return a + b; }
+
+   If the compiler supports it, try to always inline the function even if no
+   optimization level was specified. */
+#if defined(__GNUC__) || defined(__clang__)
+#  define Py_STATIC_INLINE(TYPE) \
+       __attribute__((always_inline)) static inline TYPE
+#elif defined(_MSC_VER)
+#  define Py_STATIC_INLINE(TYPE) \
+       static __forceinline TYPE
+#else
+#  define Py_STATIC_INLINE(TYPE) static inline TYPE
+#endif
+
+
 /* Py_MEMCPY is kept for backwards compatibility,
  * see https://bugs.python.org/issue28126 */
 #define Py_MEMCPY memcpy