Document CodeType.replace (GH-17776)

(cherry picked from commit 22424c02e51fab3b62cbe255d0b87d1b55b9a6c3)

Co-authored-by: Anthony Sottile <asottile@umich.edu>
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index f0b62ec..522e1a9 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -610,7 +610,7 @@
     co_name: unicode(c_default="self->co_name") = None
     co_lnotab: PyBytesObject(c_default="(PyBytesObject *)self->co_lnotab") = None
 
-Return a new code object with new specified fields.
+Return a copy of the code object with new values for the specified fields.
 [clinic start generated code]*/
 
 static PyObject *
@@ -622,7 +622,7 @@
                   PyObject *co_varnames, PyObject *co_freevars,
                   PyObject *co_cellvars, PyObject *co_filename,
                   PyObject *co_name, PyBytesObject *co_lnotab)
-/*[clinic end generated code: output=25c8e303913bcace input=77189e46579ec426]*/
+/*[clinic end generated code: output=25c8e303913bcace input=d9051bc8f24e6b28]*/
 {
 #define CHECK_INT_ARG(ARG) \
         if (ARG < 0) { \