glsl: Convert piles of foreach_iter to foreach_list_safe.

In these cases, we edit the list (or at least might be), so we use the
foreach_list_safe variant.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glsl/opt_copy_propagation.cpp

@@ -292,8 +292,8 @@ ir_copy_propagation_visitor::kill(ir_variable *var)
    assert(var != NULL);
 
    /* Remove any entries currently in the ACP for this kill. */
-   foreach_iter(exec_list_iterator, iter, *acp) {
-      acp_entry *entry = (acp_entry *)iter.get();
+   foreach_list_safe(n, acp) {
+      acp_entry *entry = (acp_entry *) n;
 
       if (entry->lhs == var || entry->rhs == var) {
 	 entry->remove();