patch 8.2.3334: Vim9: not enough tests run with Vim9

Problem:    Vim9: not enough tests run with Vim9.
Solution:   Run a few more tests in Vim9 script and :def function. Fix
            islocked().  Fix error for locking local variable.
diff --git a/src/evalfunc.c b/src/evalfunc.c
index efda01f..b90c6d7 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -6556,7 +6556,8 @@
 	return;
 
     end = get_lval(tv_get_string(&argvars[0]), NULL, &lv, FALSE, FALSE,
-			     GLV_NO_AUTOLOAD | GLV_READ_ONLY, FNE_CHECK_START);
+			     GLV_NO_AUTOLOAD | GLV_READ_ONLY | GLV_NO_DECL,
+			     FNE_CHECK_START);
     if (end != NULL && lv.ll_name != NULL)
     {
 	if (*end != NUL)