gh-160147: Inline PyObject_IS_GC() in _PyObject_GC_MAY_BE_TRACKED() (#161189)

Move _PyType_IS_GC() and _PyObject_IS_GC() from pycore_object.h to
pycore_gc.h. Replace PyObject_IS_GC() call with _PyObject_IS_GC() in
_PyObject_GC_MAY_BE_TRACKED().

Help the compiler to inline _PyObject_IS_GC() code in
_PyObject_GC_MAY_BE_TRACKED(), especially when LTO is not used.

Author: vstinner

Include/internal/pycore_gc.h

@@ -80,10 +80,26 @@ static inline int _PyObject_GC_IS_TRACKED(PyObject *op) {
 }
 #define _PyObject_GC_IS_TRACKED(op) _PyObject_GC_IS_TRACKED(_Py_CAST(PyObject*, op))
 
+// Fast inlined version of PyType_IS_GC()
+static inline int
+_PyType_IS_GC(PyTypeObject *type)
+{
+    return (type->tp_flags & Py_TPFLAGS_HAVE_GC) != 0;
+}
+
+// Fast inlined version of PyObject_IS_GC()
+static inline int
+_PyObject_IS_GC(PyObject *obj)
+{
+    PyTypeObject *type = Py_TYPE(obj);
+    return (_PyType_IS_GC(type)
+            && (type->tp_is_gc == NULL || type->tp_is_gc(obj)));
+}
+
 /* True if the object may be tracked by the GC in the future, or already is.
    This can be useful to implement some optimizations. */
 static inline int _PyObject_GC_MAY_BE_TRACKED(PyObject *obj) {
-    if (!PyObject_IS_GC(obj)) {
+    if (!_PyObject_IS_GC(obj)) {
         return 0;
     }
     if (PyTuple_CheckExact(obj)) {

Include/internal/pycore_object.h

@@ -816,18 +816,6 @@ _PyObject_GET_WEAKREFS_LISTPTR_FROM_OFFSET(PyObject *op)
     return (PyWeakReference **)((char *)op + offset);
 }
 
-// Fast inlined version of PyType_IS_GC()
-#define _PyType_IS_GC(t) _PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC)
-
-// Fast inlined version of PyObject_IS_GC()
-static inline int
-_PyObject_IS_GC(PyObject *obj)
-{
-    PyTypeObject *type = Py_TYPE(obj);
-    return (_PyType_IS_GC(type)
-            && (type->tp_is_gc == NULL || type->tp_is_gc(obj)));
-}
-
 // Fast inlined version of PyObject_Hash(). Dictionaries are very
 // likely to include string keys (class and instance attributes,
 // json, ...) so we include a fast path for strings.