patch 8.2.3511: Vim9: entry for loop variable is created every round

Problem:    Vim9: entry for loop variable is created every round.
Solution:   Only create the entry once. (closes #8996)
diff --git a/src/evalvars.c b/src/evalvars.c
index 4cc0fa8..fbf2d68 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -3319,7 +3319,7 @@
 		    goto failed;
 		}
 
-		if (var_in_vim9script)
+		if (var_in_vim9script && (flags & ASSIGN_FOR_LOOP) == 0)
 		{
 		    where_T where = WHERE_INIT;
 
@@ -3331,7 +3331,8 @@
 			goto failed;
 		}
 
-		if (var_check_permission(di, name) == FAIL)
+		if ((flags & ASSIGN_FOR_LOOP) == 0
+				     && var_check_permission(di, name) == FAIL)
 		    goto failed;
 	    }
 	    else
diff --git a/src/version.c b/src/version.c
index d1f079c..f4e9f9f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3511,
+/**/
     3510,
 /**/
     3509,
diff --git a/src/vim9script.c b/src/vim9script.c
index ca245b2..9696dfe 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -978,8 +978,9 @@
 	// legacy script doesn't store variable types
 	return NULL;
 
-    // Find the svar_T in sn_var_vals.
-    for (idx = 0; idx < si->sn_var_vals.ga_len; ++idx)
+    // Find the svar_T in sn_var_vals.  Start at the end, in a for loop the
+    // variable was added at the end.
+    for (idx = si->sn_var_vals.ga_len - 1; idx >= 0; --idx)
     {
 	svar_T    *sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;