py: Remove unused and unneeded SystemError exception.

It's purpose is for internal errors that are not catastrophic (ie not as
bad as RuntimeError).  Since we don't use it, we don't need it.

py/builtintables.c

@@ -136,7 +136,6 @@ STATIC const mp_map_elem_t mp_builtin_object_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_RuntimeError), (mp_obj_t)&mp_type_RuntimeError },
     { MP_OBJ_NEW_QSTR(MP_QSTR_StopIteration), (mp_obj_t)&mp_type_StopIteration },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SyntaxError), (mp_obj_t)&mp_type_SyntaxError },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_SystemError), (mp_obj_t)&mp_type_SystemError },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SystemExit), (mp_obj_t)&mp_type_SystemExit },
     { MP_OBJ_NEW_QSTR(MP_QSTR_TypeError), (mp_obj_t)&mp_type_TypeError },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ValueError), (mp_obj_t)&mp_type_ValueError },

py/obj.h

@@ -339,7 +339,6 @@ 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_StopIteration;
 extern const mp_obj_type_t mp_type_SyntaxError;
-extern const mp_obj_type_t mp_type_SystemError;
 extern const mp_obj_type_t mp_type_SystemExit;
 extern const mp_obj_type_t mp_type_TypeError;
 extern const mp_obj_type_t mp_type_ValueError;

py/objexcept.c

@@ -268,7 +268,7 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
       MP_DEFINE_EXCEPTION_BASE(IndentationError)
       MP_DEFINE_EXCEPTION(TabError, IndentationError)
       */
-  MP_DEFINE_EXCEPTION(SystemError, Exception)
+  //MP_DEFINE_EXCEPTION(SystemError, Exception)
   MP_DEFINE_EXCEPTION(TypeError, Exception)
   MP_DEFINE_EXCEPTION(ValueError, Exception)
     //TODO: Implement UnicodeErrors which take arguments

py/qstrdefs.h

@@ -117,7 +117,6 @@ Q(OSError)
 Q(OverflowError)
 Q(RuntimeError)
 Q(SyntaxError)
-Q(SystemError)
 Q(SystemExit)
 Q(TypeError)
 Q(UnboundLocalError)

tests/basics/exceptpoly.py

@@ -298,15 +298,15 @@ except SyntaxError:
 #except SyntaxWarning:
 #    print("Caught SyntaxWarning")
 
-try:
-    raise SystemError
-except Exception:
-    print("Caught SystemError via Exception")
+#try:
+#    raise SystemError
+#except Exception:
+#    print("Caught SystemError via Exception")
 
-try:
-    raise SystemError
-except SystemError:
-    print("Caught SystemError")
+#try:
+#    raise SystemError
+#except SystemError:
+#    print("Caught SystemError")
 
 #try:
 #    raise TabError

tests/micropython/viper_misc.py

@@ -69,10 +69,10 @@ print(sorted(list(viper_set(1, 2))))
 # raising an exception
 @micropython.viper
 def viper_raise(x:int):
-    raise SystemError(x)
+    raise OSError(x)
 try:
     viper_raise(1)
-except SystemError as e:
+except OSError as e:
     print(repr(e))
 
 # this doesn't work at the moment

tests/micropython/viper_misc.py.exp

@@ -8,6 +8,6 @@
 (1, 3)
 [1, 3]
 [1, 3]
-SystemError(1,)
+OSError(1,)
 1
 1