(IdnToUnicode): Define.
(FreeAddrInfoW): Define.
(GetAddrInfoW): Define.
(GetNameInfoW): Define.
* net.cc: Drop W. Richard STEVENS libgai implementation.
(cygwin_freeaddrinfo): Move code from ipv4_freeaddrinfo here. Move
definition up in file to avoid forward declaration in ga_duplist.
(ga_dup): Take addrinfoW as input. Add parameters to get IDN flags
and to set error value. Handle IDN flags and especially AI_CANONIDN.
Convert input wchar_t ai_canonname string to multibyte for output.
(ga_duplist): Add parameters to get IDN flags and to set error value
and propagate to ga_dup. Call cygwin_freeaddrinfo.
(gai_errmap): Add comments. Align error strings to GLibc. Add
EAI_IDN_ENCODE entry.
(get_ipv6_funcs): Remove.
(load_ipv6_guard): Remove.
(ipv6_inited): Remove.
(load_ipv6): Remove.
(load_ipv6_funcs): Remove.
(cygwin_getaddrinfo): Drop calling load_ipv6. Handle AI_IDN* flags.
Convert input strings to wchar_t and call GetAddrInfoW/FreeAddrInfoW.
In case hints is NULL, set default ai_flags explicitely to
AI_V4MAPPED | AI_ADDRCONFIG, as documented for Glibc. Only add AI_ALL
if AI_ADDRCONFIG is not given. Unconditionally add Windows-specific
AI_DISABLE_IDN_ENCODING to ai_flags to make IDN behaviour compatible
to Glibc even on Windows 8 and later.
(cygwin_getnameinfo): Drop calling load_ipv6. Handle NI_IDN* flags.
Call GetNameInfoW and convert returned strings from wchar_t to
multibyte.
* include/netdb.h: Add comments to describe flags and error values.
(AI_*): Define all flags using hex values for clearness.
(AI_IDN): Define.
(AI_CANONIDN): Define.
(AI_IDN_ALLOW_UNASSIGNED): Define.
(AI_IDN_USE_STD3_ASCII_RULES): Define.
(NI_*): Define all flags using hex values for clearness.
(NI_IDN): Define.
(NI_IDN_ALLOW_UNASSIGNED): Define.
(NI_IDN_USE_STD3_ASCII_RULES): Define.
(EAI_IDN_ENCODE): Define.