[Pitch] InlineArray type sugar

[xwu (Xiaodi Wu)]

@Pippin

Should we be taking into consideration the future of bare meta types?

It is not just future—it is also past and present (SE-0090, reviewed 2016, deferred from Swift 3, returned for revision).

@Chris_Lattner

The community and core team all want this proposal (or something like it) to succeed, but the core team identified several serious implementation concerns with the proposal