HTTP/2: reject self-dependent streams. Per RFC7540, a stream cannot depend on itself. Previously, this requirement was enforced on PRIORITY frames, but not on HEADERS frames and due to the implementation details nginx worker would crash (stack overflow) while opening self-dependent stream. Found with afl-fuzz. Signed-off-by: Piotr Sikora <piotrsikora@google.com>

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_HEADERS_H

#ifndef $have
#define $have  1
#endif

END