[SR-7997] Source compatibility (4.1 -> 4.2) when multiple properties have the same name

[alexito4]

Previous ID	SR-7997
Radar	rdar://problem/41161407
Original Reporter	@alexito4
Type	Bug

Attachment: Download

Environment

Xcode 10 (beta 1)

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, 4.2Regression
Assignee	None
Priority	Medium

md5: 2bffeaa3a20b70d3693e0fa543873aba

Issue Description:

Trying to compile a project with Xcode 10 beta gives a compiler error.
The issue comes from using TTTAttributedLabel as it redefines the "text" property from UILabel. TTTAttributedLabel/TTTAttributedLabel/blob/master/TTTAttributedLabel/TTTAttributedLabel.h#L77

@belkadan provided some context in the forum https://forums.swift.org/t/swift-4-2-source-compatibility/

I attached a sample project with the issue.
The project compiles fine in Xcode 9.4 but fails in Xcode 10.

[belkadan]

@swift-ci create