* c-decl.c (grokdeclarator): Give zero-length arrays size zero.

    * c-decl.c (grokdeclarator): Give zero-length arrays size zero.
        Remove dead code.
        * c-typeck.c (push_init_level): Move checks for flexible array
        members and zero length arrays ...
        (pop_init_level): ... here.  Silently discard empty initializations.
        Remove dead code.
        * varasm.c (output_constructor): Update for sizeof change to
        zero-length arrays.

        * extend.texi (Zero Length): Clarify semantics.

        * gcc.dg/940510-1.c: Update expected error wording.
        * gcc.dg/array-2.c, gcc.dg/array-3.c, gcc.dg/array-4.c: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@38678 138bc75d-0d04-0410-961f-82ee72b054a4