[Bug 41703] Make LdrUnloadDLL a stub if libc does not unload module after dlclose

https://bugs.winehq.org/show_bug.cgi?id=41703

[e-mail] changed:

What    |Removed                     |Added
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            Summary|LdrUnloadDll is not suit    |Make LdrUnloadDLL a stub if
                   |for musl(musl lacks unload  |libc does not unload module
                   |support though it has a     |after dlclose
                   |dlclose())                  |