Issue Description:

Initializing a Swift project on macOS 10.15.2 with Swift 5.1.3 and Xcode 11.3 via

> swift package init --type executable

, then generating an Xcode project with

> swift package generate-xcodeproj

and trying to compile in Xcode fails with:

> cannot load module 'swift' as 'Swift'

Renaming the package

> let package = Package(
> name: "bla",

, the target

> .target(
> name: "bla",

and the Sources directory

> Sources/bla

makes it work.