[SR-4333] Consider updating the existing tuple-design for function parameters

[bob-wilson]

Previous ID	SR-4333
Radar	rdar://problem/31408030
Original Reporter	@bob-wilson
Type	Task
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Task, AffectsABI, Runtime
Assignee	@xedin
Priority	Medium

md5: 966e92e5baffa6d6f76e9cb594eb2d82

Issue Description:

From the ABI Stability manifesto's section on Function Metadata: "Function parameters are currently modeled with a tuple-based design, but this should be updated to match modern Swift"

[belkadan]

Related issues: function type mangling and the compiler representation of function types.

[bob-wilson]

@swift-ci create

[bob-wilson]

The description of this issue is missing some context. This comes from the "Function Metadata" section of the ABI Stability manifesto (https://github.com/apple/swift/blob/master/docs/ABIStabilityManifesto.md) and was specifically intended to address function metadata issues.

Pavel has completed a re-design of function metadata in #12812 and #12833 and this issue has been resolved as part of that work.