Better error messages for vararg-table fields

ldebug.c

@@ -580,7 +580,7 @@ static const char *getobjname (const Proto *p, int lastpc, int reg,
         kname(p, k, name);
         return isEnv(p, lastpc, i, 1);
       }
-      case OP_GETTABLE: {
+      case OP_GETTABLE: case OP_GETVARG: {
         int k = GETARG_C(i);  /* key index */
         rname(p, lastpc, k, name);
         return isEnv(p, lastpc, i, 0);

testes/errors.lua

@@ -159,6 +159,9 @@ assert(not string.find(doit"aaa={13}; local bbbb=1; aaa[bbbb](3)", "'bbbb'"))
 checkmessage("aaa={13}; local bbbb=1; aaa[bbbb](3)", "number")
 checkmessage("aaa=(1)..{}", "a table value")
 
+checkmessage("local function foo (...t) return t.xx + 1 end; foo()",
+             "field 'xx'")
+
 -- bug in 5.4.6
 checkmessage("a = {_ENV = {}}; print(a._ENV.x + 1)", "field 'x'")