The function `CreateHardLink()` is available in all supported Windows
versions (even since Windows XP), so there is no more need to resolve it
at runtime.
Helped-by: Max Kirillov <max@max630.net> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>