[SR-15556] Duplicate conformance sections generated from synthesized conformance in Docc

[heckj]

Previous ID	SR-15556
Radar	rdar://problem/86089651
Original Reporter	@heckj
Type	Bug

Attachment: Download

Environment

Happens with both Xcode 13.1 and Version 13.2 beta 2 (13C5081f)

Additional Detail from JIRA

Votes	0
Component/s	Swift-DocC, Swift-DocC-Render
Labels	Bug
Assignee	None
Priority	Medium

md5: deb5998f8c142585ed2da631bc6fe8b3

Issue Description:

I'm not certain where the duplication comes from - but when I'm working on documenting a struct that has synthesized conformances, I'm seeing some replicated "Default Implementations" sections with the various operators.

The specific case that illustrates this is a struct that has an extenion where it conforms to Comparable. For detail, an example struct:

```
public struct ObjectId: Equatable, Hashable, Codable, ExpressibleByStringLiteral, ExpressibleByStringInterpolation {

init(_ objectId: String = UUID().uuidString)

{ self.objectId = objectId }

let objectId: String

public init(from decoder: Decoder) throws

{ let container = try decoder.singleValueContainer() self.objectId = try container.decode(String.self) }

public func encode(to encoder: Encoder) throws

{ var container = encoder.singleValueContainer() try container.encode(objectId) }

static let root: ObjectId = "_root"
static let head: ObjectId = "_head"

public init(stringLiteral value: StringLiteralType)

{ self.objectId = value }

func parseOpId() -> (counter: Int, actorId: String)? {
guard objectId.contains("@") else

{ return nil }

let splitted = objectId.split(separator: "@")
return (counter: Int(String(splitted[0]))!, actorId: String(splitted[1]))
}
}

extension ObjectId: Comparable {
public static func < (lhs: ObjectId, rhs: ObjectId) -> Bool

{ return lhs.objectId < rhs.objectId }

}
```

The resulting documentation exposed (through Xcode, or `docc-preview` on the CLI) shows the attached screenshot. Within each of the sections listed as 'Implementations' with nothing preceding it, are the same operators- screenshot of those attached as well. They're all from Comparable:
```
static func ... (Self) -> PartialRangeThrough<Self>
static func ... (Self) -> PartialRangeFrom<Self>
static func ... (Self, Self) -> ClosedRange<Self>
static func ..< (Self) -> PartialRangeUpTo<Self>
static func ..< (Self, Self) -> Range<Self>
```

[franklinsch]

@swift-ci create