c-typeck.c (really_start_incremental_init): Discriminate between zero-length arrays and flexible arrays.

* c-typeck.c (really_start_incremental_init): Discriminate
between zero-length arrays and flexible arrays.
(push_init_level): Detect zero-length arrays and handle them
like fixed-sized arrays.
* expr.c (store_constructor): Handle zero-length arrays and
flexible arrays correctly.
* doc/extend.texi: Update zero-length array notes.

* gcc.dg/20000926-1.c: Update expected warning messages.
* gcc.dg/array-2.c: Likewise, and test for warnings too.
* gcc.dg/array-4.c: Likewise, and don't verify the zero-length
array.

From-SVN: r45714