[PATCH v2 0/1] MR152: include: Make IShellItem::BindToHandler's pbc parameter as [unique].

[Jinoh Kang (＠iamahuman)]

The Windows SDK headers makes it clear that the IBindCtx parameter of
BindToHandler is optional.  Bring Wine's definition in sync with those.

Thanks @nsivov for pointing this out.

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  v2: include: Mark IShellItem::BindToHandler's pbc parameter as [unique].

https://gitlab.winehq.org/wine/wine/-/merge_requests/152