http://source.winehq.org/source/dlls/ntdll/
It's fairly harmless, there is some assembly in there but I don't remember seeing any code which assumed an executable stack.
i've looked at it and as i suggested yesterday, it's a false positive. what happens here is that relay32.s doesn't emit a .note.GNU-stack section at all, which when linked together with other .o files that do, will result in an executable PT_GNU_STACK program header. the solution is to add
.section .note.GNU-stack,"",@progbits
to relat32.s and it'll be ok. alternatively, you can forcefully assemble with --noexecstack or link the .so with '-z noexecstack' (or -Wl,-z,noexecstack for gcc) which will override the .note.GNU-stack markings.