(set_init_index): Don't allow variable indices.

(set_init_index): Don't allow variable indices.

(output_init_element): When putting an elt into a
CONSTRUCTOR, always set the TREE_PURPOSE (even for arrays).
Copy the node if it's an INTEGER_CST.
(output_pending_init_elements): If have gap and not incremental,
advance constructor_unfilled_fields or constructor_unfilled_index.

(push_init_level): Pop any implicit levels
that have been filled up.
Don't die if constructor_type is 0.
(process_init_element): If VALUE is 0 for union type,
update constructor_bit_index.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@5317 138bc75d-0d04-0410-961f-82ee72b054a4