Test: add coverage for borrowing get

[kavon]

resolves rdar://132915515

[kavon]

@swift-ci smoke test

[kavon]

--
/home/build-user/swift/test/Interpreter/moveonly.swift:7:8: error: no such module 'Foundation'
  5 | 
  6 | import StdlibUnittest
  7 | import Foundation
    |        `- error: no such module 'Foundation'
  8 | 
  9 | defer { runAllTests() }

--

Should split this test-case out, since we should use an imported type.

[kavon]

@swift-ci smoke test

[kavon]

@swift-ci smoke test