py/objexcept: Remove optional TimeoutError exception.

TimeoutError was added back in 077812b2ab for
the cc3200 port. In f522849a4d the cc3200
port enabled use of it in the socket module aliased to socket.timeout.  So
it was never added to the builtins.  Then it was replaced by
OSError(ETIMEDOUT) in 047af9b10b.

The esp32 port enables this exception, since the very beginning of that
port, but it could never be accessed because it's not in builtins.

It's being removed: 1) to not encourage its use; 2) because there are a lot
of other OSError subclasses which are not defined at all, and having
TimeoutError is a bit inconsistent.

Note that ports can add anything to the builtins via MICROPY_PORT_BUILTINS.
And they can also define their own exceptions using the
MP_DEFINE_EXCEPTION() macro.

ports/esp32/mpconfigport.h

@@ -78,7 +78,6 @@
 #define MICROPY_PY_BUILTINS_PROPERTY        (1)
 #define MICROPY_PY_BUILTINS_RANGE_ATTRS     (1)
 #define MICROPY_PY_BUILTINS_ROUND_INT       (1)
-#define MICROPY_PY_BUILTINS_TIMEOUTERROR    (1)
 #define MICROPY_PY_ALL_SPECIAL_METHODS      (1)
 #define MICROPY_PY_BUILTINS_COMPILE         (1)
 #define MICROPY_PY_BUILTINS_ENUMERATE       (1)

py/mpconfig.h

@@ -959,11 +959,6 @@ typedef double mp_float_t;
 #define MICROPY_PY_BUILTINS_ROUND_INT (0)
 #endif
 
-// Whether to support timeout exceptions (like socket.timeout)
-#ifndef MICROPY_PY_BUILTINS_TIMEOUTERROR
-#define MICROPY_PY_BUILTINS_TIMEOUTERROR (0)
-#endif
-
 // Whether to support complete set of special methods for user
 // classes, or only the most used ones. "Inplace" methods are
 // controlled by MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS below.

py/obj.h

@@ -650,7 +650,6 @@ extern const mp_obj_type_t mp_type_MemoryError;
 extern const mp_obj_type_t mp_type_NameError;
 extern const mp_obj_type_t mp_type_NotImplementedError;
 extern const mp_obj_type_t mp_type_OSError;
-extern const mp_obj_type_t mp_type_TimeoutError;
 extern const mp_obj_type_t mp_type_OverflowError;
 extern const mp_obj_type_t mp_type_RuntimeError;
 extern const mp_obj_type_t mp_type_StopAsyncIteration;

py/objexcept.c

@@ -303,9 +303,6 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
     MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
     */
   MP_DEFINE_EXCEPTION(OSError, Exception)
-#if MICROPY_PY_BUILTINS_TIMEOUTERROR
-    MP_DEFINE_EXCEPTION(TimeoutError, OSError)
-#endif
     /*
     MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
     MP_DEFINE_EXCEPTION(ChildProcessError, OSError)
@@ -319,6 +316,7 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
     MP_DEFINE_EXCEPTION(NotADirectoryError, OSError)
     MP_DEFINE_EXCEPTION(PermissionError, OSError)
     MP_DEFINE_EXCEPTION(ProcessLookupError, OSError)
+    MP_DEFINE_EXCEPTION(TimeoutError, OSError)
     MP_DEFINE_EXCEPTION(FileExistsError, OSError)
     MP_DEFINE_EXCEPTION(FileNotFoundError, OSError)
     MP_DEFINE_EXCEPTION(ReferenceError, Exception)