[3.13] gh-137668: Document that ord() supports also bytes and bytearray (GH-137669) (GH-137704)

(cherry picked from commit 35759fe2fa)

Python/bltinmodule.c

@@ -1969,15 +1969,21 @@ builtin_oct(PyObject *module, PyObject *number)
 /*[clinic input]
 ord as builtin_ord
 
-    c: object
+    character as c: object
     /
 
-Return the Unicode code point for a one-character string.
+Return the ordinal value of a character.
+
+If the argument is a one-character string, return the Unicode code
+point of that character.
+
+If the argument is a bytes or bytearray object of length 1, return its
+single byte value.
 [clinic start generated code]*/
 
 static PyObject *
 builtin_ord(PyObject *module, PyObject *c)
-/*[clinic end generated code: output=4fa5e87a323bae71 input=3064e5d6203ad012]*/
+/*[clinic end generated code: output=4fa5e87a323bae71 input=98d38480432e1177]*/
 {
     long ord;
     Py_ssize_t size;

Python/clinic/bltinmodule.c.h

@@ -806,10 +806,16 @@ PyDoc_STRVAR(builtin_oct__doc__,
     {"oct", (PyCFunction)builtin_oct, METH_O, builtin_oct__doc__},
 
 PyDoc_STRVAR(builtin_ord__doc__,
-"ord($module, c, /)\n"
+"ord($module, character, /)\n"
 "--\n"
 "\n"
-"Return the Unicode code point for a one-character string.");
+"Return the ordinal value of a character.\n"
+"\n"
+"If the argument is a one-character string, return the Unicode code\n"
+"point of that character.\n"
+"\n"
+"If the argument is a bytes or bytearray object of length 1, return its\n"
+"single byte value.");
 
 #define BUILTIN_ORD_METHODDEF    \
     {"ord", (PyCFunction)builtin_ord, METH_O, builtin_ord__doc__},
@@ -1228,4 +1234,4 @@ builtin_issubclass(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=435d3f286a863c49 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=f686ad843368963c input=a9049054013a1b77]*/