py: Make compiler return a proper exception on SyntaxError.

py/builtinevex.c

@@ -64,9 +64,9 @@ STATIC mp_obj_t parse_compile_execute(mp_obj_t o_in, mp_parse_input_kind_t parse
     // compile the string
     mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, false);
 
-    if (module_fun == mp_const_none) {
-        // TODO handle compile error correctly
-        return mp_const_none;
+    // check if there was a compile error
+    if (mp_obj_is_exception_instance(module_fun)) {
+        nlr_raise(module_fun);
     }
 
     // complied successfully, execute it