[FEATURE REQUEST] Mark gio::Icon as Send and Sync

[kavan-mevada]

[sdroege]

Someone will need to check if the C implementation of those types is guaranteed to be thread-safe, always.

[AbuShawarib]

GBytesIcon has a simple pointer for the bytes and uses memcmp when using equal with the given pointers. It seems obvious that changing pointers when memcmp is running makes its results obsolete. Other types also has direct pointer assignment for main content pointers.

[sdroege]

The question is not whether a single implementation of the interface is Send+Sync but if all valid implementations of the interface must be Send+Sync.