eolian: allow trailing comma on last enum item (just like C)

src/lib/eolian/eo_parser.c

@@ -616,7 +616,7 @@ parse_enum(Eo_Lexer *ls, const char *name, Eina_Bool is_extern,
         if (want_next)
           eo_lexer_get(ls);
         FILL_DOC(ls, fdef, doc);
-        if (!want_next)
+        if (!want_next || ls->t.token == '}')
           break;
      }
    check_match(ls, '}', '{', bline, bcolumn);

src/tests/eolian/data/enum.eo

@@ -13,7 +13,7 @@ enum Bar {
 enum Baz {
     flag1 = 1 << 0,
     flag2 = 1 << 1,
-    flag3 = 1 << 2
+    flag3 = 1 << 2, // testing trailing comma on last item
 }
 
 enum Name.Spaced {