Both the Msys2 and Cygwin runtimes make use of
FILE_DISPOSITION_IGNORE_READONLY_ATTRIBUTE in their implementations of the
unlink() system call. This enables these routines to delete a read-only file
without first modifying the attributes.

https://github.com/msys2/msys2-runtime/blob/msys2-3.4.3/winsup/cygwin/syscalls.cc#L724
https://www.cygwin.com/git/?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/syscalls.cc#l726

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=50771Signed-off-by: Joel Holdsworth <joel@airwebreathe.org.uk>