patch 9.0.1390: FOR_ALL_ macros are defined in an unexpected file

Problem:    FOR_ALL_ macros are defined in an unexpected file.
Solution:   Move FOR_ALL_ macros to macros.h.  Add FOR_ALL_HASHTAB_ITEMS.
            (Yegappan Lakshmanan, closes #12109)
diff --git a/src/userfunc.c b/src/userfunc.c
index 9e24b79..878e07f 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -2313,7 +2313,7 @@
 
 	// Make a copy of the a: variables, since we didn't do that above.
 	todo = (int)fc->fc_l_avars.dv_hashtab.ht_used;
-	for (hi = fc->fc_l_avars.dv_hashtab.ht_array; todo > 0; ++hi)
+	FOR_ALL_HASHTAB_ITEMS(&fc->fc_l_avars.dv_hashtab, hi, todo)
 	{
 	    if (!HASHITEM_EMPTY(hi))
 	    {
@@ -3296,7 +3296,7 @@
     while (todo > 0)
     {
 	todo = func_hashtab.ht_used;
-	for (hi = func_hashtab.ht_array; todo > 0; ++hi)
+	FOR_ALL_HASHTAB_ITEMS(&func_hashtab, hi, todo)
 	    if (!HASHITEM_EMPTY(hi))
 	    {
 		fp = HI2UF(hi);
@@ -3353,7 +3353,7 @@
     while (todo > 0)
     {
 	todo = func_hashtab.ht_used;
-	for (hi = func_hashtab.ht_array; todo > 0; ++hi)
+	FOR_ALL_HASHTAB_ITEMS(&func_hashtab, hi, todo)
 	    if (!HASHITEM_EMPTY(hi))
 	    {
 		// clear the def function index now
@@ -3385,7 +3385,7 @@
     while (func_hashtab.ht_used > skipped)
     {
 	todo = func_hashtab.ht_used;
-	for (hi = func_hashtab.ht_array; todo > 0; ++hi)
+	FOR_ALL_HASHTAB_ITEMS(&func_hashtab, hi, todo)
 	    if (!HASHITEM_EMPTY(hi))
 	    {
 		--todo;