gh-46236: Add missing PyUnicode_FromOrdinal() doc (#132040)

(cherry picked from commit 8768df2)

Author: rruuaanng

Doc/c-api/unicode.rst

@@ -589,6 +589,14 @@ APIs:
    Objects other than Unicode or its subtypes will cause a :exc:`TypeError`.
 
 
+.. c:function:: PyObject* PyUnicode_FromOrdinal(int ordinal)
+
+   Create a Unicode Object from the given Unicode code point *ordinal*.
+
+   The ordinal must be in ``range(0x110000)``. A :exc:`ValueError` is
+   raised in the case it is not.
+
+
 .. c:function:: PyObject* PyUnicode_FromEncodedObject(PyObject *obj, \
                                const char *encoding, const char *errors)
 

Doc/data/refcounts.dat

@@ -2756,6 +2756,9 @@ PyUnicode_FromFormatV:PyObject*::+1:
 PyUnicode_FromFormatV:const char*:format::
 PyUnicode_FromFormatV:va_list:args::
 
+PyUnicode_FromOrdinal:PyObject*::+1:
+PyUnicode_FromOrdinal:int:ordinal::
+
 PyUnicode_GetDefaultEncoding:const char*:::
 PyUnicode_GetDefaultEncoding::void::