repl: make the sources more portable to cl
repl: make the sources more portable to cl

This allows us to build with cl as well as as clang.  Furthermore, it
allows building on Windows.  A follow up change would actually load the
swiftCore DLL.

apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb