- Change distinct -> typedef.

- Order of attribute declaration is changed for `alias`.
- Added `LANGUAGE_DEV_VERSION` env constant.
- Rename `anyfault` -> `fault`.
- Changed `fault` -> `faultdef`.
- Added `attrdef` instead of `alias` for attribute aliases.

test/test_suite/struct/struct_bad_member.c3

@@ -7,7 +7,7 @@ struct Foo2 {
   Void bar; // #error: Members cannot be of
 }
 
-distinct Void2 = void;
+typedef Void2 = void;
 struct Foo3 {
   Void2 bar; // #error: has unknown size
 }