[SR-8665] Implementation detail _value manifest in user code

[jepers]

Previous ID	SR-8665
Radar	None
Original Reporter	@jepers
Type	Bug

Environment

Xcode 10 beta 6

Additional Detail from JIRA

Votes	0
Component/s	LLDB for Swift, Standard Library
Labels	Bug
Assignee	None
Priority	Medium

md5: 795972b46113982fd58b041cd1cc6a9c

Issue Description:

For details see: https://forums.swift.org/t/whats-this-value-property/15660

[jckarter]

Maybe LLDB doesn't look through type sugar when picking a data formatter? It looks like in the `(Int)` case it's using the default struct data formatter.