[SR-7865] swift-corelibs-foundation does not compile on macOS after 'as' bridging was merged

[spevans]

Previous ID	SR-7865
Radar	None
Original Reporter	@spevans
Type	Bug
Status	Closed
Resolution	Done

Environment

macOS 10.13.5

Xcode: 9.4

Toolchain: Swift Development snapshot 2018-06-02 (a)

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug
Assignee	@millenomi
Priority	Medium

md5: df94333d3f507d4b147b6adfedcc4533

Issue Description:

After the 'as' bridging for Linux was merged (#1526 swift-corelibs-foundation does not build in Xcode, it has the error:

Foundation/Bridging.swift:58:57: Use of undeclared type '_NSSwiftValue'

[spevans]

cc @millenomi

[millenomi]

#1579