[SR-4343] Decide what class metadata is opaque for library evolution (resilience)

[bob-wilson]

Previous ID	SR-4343
Radar	rdar://problem/31408029
Original Reporter	@bob-wilson
Type	Task
Status	Resolved
Resolution	Done

Attachment: Download

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Task, AffectsABI
Assignee	@duyduongdevelopers (JIRA)
Priority	Medium

md5: 1e052641a819da11506e71ae7ed0906d

Issue Description:

From the Class Metadata section of the ABI Stability manifesto:

"Library evolution may present many changes to what exactly is present and will likely make many of the contents opaque to accommodate changes."

We need to decide what the class metadata should contain and what should be opaque as part of locking down the ABI.

[bob-wilson]

@swift-ci create

[slavapestov]

I think this is done. We've essentially made everything opaque except for the generic parameter area.