bpo-36793: Remove unneeded __str__ definitions. (GH-13081)

Classes that define __str__ the same as __repr__ can
just inherit it from object.
diff --git a/Objects/boolobject.c b/Objects/boolobject.c
index b92fafe..508ea61 100644
--- a/Objects/boolobject.c
+++ b/Objects/boolobject.c
@@ -147,7 +147,7 @@
     0,                                          /* tp_as_mapping */
     0,                                          /* tp_hash */
     0,                                          /* tp_call */
-    bool_repr,                                  /* tp_str */
+    0,                                          /* tp_str */
     0,                                          /* tp_getattro */
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 6e3d47b..cae2bf1 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -1129,7 +1129,7 @@
     0,                                          /* tp_as_mapping */
     (hashfunc)complex_hash,                     /* tp_hash */
     0,                                          /* tp_call */
-    (reprfunc)complex_repr,                     /* tp_str */
+    0,                                          /* tp_str */
     PyObject_GenericGetAttr,                    /* tp_getattro */
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index b952df8..adb9b80 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1923,7 +1923,7 @@
     0,                                          /* tp_as_mapping */
     (hashfunc)float_hash,                       /* tp_hash */
     0,                                          /* tp_call */
-    (reprfunc)float_repr,                       /* tp_str */
+    0,                                          /* tp_str */
     PyObject_GenericGetAttr,                    /* tp_getattro */
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */
diff --git a/Objects/longobject.c b/Objects/longobject.c
index da697a7..9fb1fb0 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -5592,7 +5592,7 @@
     0,                                          /* tp_as_mapping */
     (hashfunc)long_hash,                        /* tp_hash */
     0,                                          /* tp_call */
-    long_to_decimal_string,                     /* tp_str */
+    0,                                          /* tp_str */
     PyObject_GenericGetAttr,                    /* tp_getattro */
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */