[3.14] gh-141004: Document PyUnicode_IS_COMPACT and PyUnicode_IS_COMPACT_ASCII macros (GH-143494) (GH-143785)

(cherry picked from commit 42f7c2d)

Co-authored-by: Yashraj <yashrajpala8@gmail.com>

Author: encukou

Doc/c-api/unicode.rst

@@ -65,6 +65,27 @@ Python:
    .. versionadded:: 3.3
 
 
+   The structure of a particular object can be determined using the following
+   macros.
+   The macros cannot fail; their behavior is undefined if their argument
+   is not a Python Unicode object.
+
+   .. c:namespace:: NULL
+
+   .. c:macro:: PyUnicode_IS_COMPACT(o)
+
+      True if *o* uses the :c:struct:`PyCompactUnicodeObject` structure.
+
+      .. versionadded:: 3.3
+
+
+   .. c:macro:: PyUnicode_IS_COMPACT_ASCII(o)
+
+      True if *o* uses the :c:struct:`PyASCIIObject` structure.
+
+      .. versionadded:: 3.3
+
+
 The following APIs are C macros and static inlined functions for fast checks and
 access to internal read-only data of Unicode objects:
 

Tools/check-c-api-docs/ignored_c_api.txt

@@ -109,9 +109,6 @@ PyUnstable_EXECUTABLE_KIND_PY_FUNCTION
 PyUnstable_EXECUTABLE_KIND_SKIP
 # cpython/pylifecycle.h
 Py_FrozenMain
-# cpython/unicodeobject.h
-PyUnicode_IS_COMPACT
-PyUnicode_IS_COMPACT_ASCII
 # pythonrun.h
 PyErr_Display
 # cpython/objimpl.h