bpo-40521: Optimize PyUnicode_New(0, maxchar) (GH-21099)

Functions of unicodeobject.c, like PyUnicode_New(), no longer check
if the empty Unicode singleton has been initialized or not. Consider
that it is always initialized. The Unicode API must not be used
before _PyUnicode_Init() or after _PyUnicode_Fini().
1 file changed