Use LinuxMain on all platforms except Darwin (#2734)
Use LinuxMain on all platforms except Darwin (#2734)

* Guard planLinuxMain only on Darwin platforms

LinuxMain is also used to run tests on WebAssembly/WASI (and potentially on Android, Windows etc)

* Append from linuxMainMap w/ all non-Darwin triples
abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager