All generic bridgeable types can bridge for all their instantiations now. Removing this ferrets out some now-unnecessary traps that check for unbridgeable parameter types.
* The buffer-pointer based init methods were passing the dispatch
data default destructor in such a way that the
@convention(block)-ness was lost. This leads to a thunk being passed
to dispatch instead of NULL. Subsequently, dispatch would reference
rather than copy the provided data.
Fixes:
SR-2050 (<rdar://problem/27293973>)
* Fix DispatchSourceSignal initialisation such that it no longer
registers for the wrong source type.
* Remove (group:) option from DispatchWorkItem, introduce group
options to `.async` methods that accept DispatchWorkItem.
* Rename `DispatchSourceType` to `DispatchSourceProtocol`
* Rework DispatchQueue attributes and flags into a less confusing
approach.
* Fixes:
SR-1817, SR-1771, SR-1770, SR-1769
<rdar://problem/26725156> <rdar://problem/26873917>
<rdar://problem/26918843> <rdar://problem/26810149>
<rdar://problem/27117023> <rdar://problem/27121422>
<rdar://problem/27236887> <rdar://problem/27337555>
