[SR-10772] Crash when mutating array of reference-type in struct on UIView prior to adding that view as a UIViewController's subview

[swift-ci]

Previous ID	SR-10772
Radar	rdar://problem/51181968
Original Reporter	JUSTINMKAUFMAN (JIRA User)
Type	Bug

Attachment: Download

Environment

Xcode 10.2.1

macOS 10.14.4

iOS 12.2 (Simulator and Real Device)

Additional Detail from JIRA

Votes	1
Component/s	Compiler, Foundation
Labels	Bug
Assignee	None
Priority	Medium

md5: aa7c36adb376caae7c60f0e368297049

Issue Description:

This code in the linked gist consistently crashes when built with the following Xcode 10.2.1 build settings:

Swift Version = 5
Enable Testability = NO
Optimization Level = -Owholemodule

Crash occurs both on Simulator and real device.

Gist:
https://gist.github.com/JUSTINMKAUFMAN/51a40d6e2771d9229dcc629512200202

Full Xcode project zip is attached.

!CrashViewController.png|width=291,height=187,thumbnail!