is duplicated by:

• SR-4459 Source location literals not set (#file, #function, #line)

Issue Description:

Here is an example main.swift:

print("From inside main.swift: #file - \(#file)")

class Test {
    let file = #file
}

print("From inside Test class: #file - \(Test().file)")

On 3.0.2, this prints out:
From inside main.swift: #file - /Users/ylin/Swift/Bugs/file-is-empty/Sources/main.swift
From inside Test class: #file - /Users/ylin/Swift/Bugs/file-is-empty/Sources/main.swift

On 3.1-DEVELOPMENT-SNAPSHOT-2017-03-19-a, this prints out:
From inside main.swift: #file - /Users/ylin/Swift/Bugs/file-is-empty/Sources/main.swift
From inside Test class: #file -

This code prints out an empty string for the `#file` debug symbol inside the class on 3.1 snapshot, on both OSX and Ubuntu 16.04, which is contrary to its behavior on 3.0.2.

Is this compiler change intentional?