win32: _mingw.h: do not undef NULL
authorgrischka <grischka>
Thu, 24 Jan 2013 18:49:58 +0000 (19:49 +0100)
committergrischka <grischka>
Thu, 24 Jan 2013 18:49:58 +0000 (19:49 +0100)
commitb89793d10a8cf1c3fa237d98cf4b656ac5aabf55
treeb263391564043defbf806cbeee18d97c57d42980
parent6b6eea60f3ff5134b990123127d3574955169a4f
win32: _mingw.h: do not undef NULL

Not wise if stddef.h was already included. This is related to commit

    3aa26a794e24a298493a2bc9d70fbd9aebf6437a

Instead hack stddef.h to have identical definition and thus
avoid the issue mentionned there.
include/stddef.h
win32/include/_mingw.h