SR-4201: DispatchSourceSignal not working on Linux#231

MadCoder merged 1 commit intoswiftlang:masterswiftlang/swift-corelibs-libdispatch:masterfrom

dgrove-oss:SR-4201-signalsourcedgrove-oss/swift-corelibs-libdispatch:SR-4201-signalsourceCopy head branch name to clipboard