fixes for swiftc compiler warnings#141

dgrove-oss wants to merge 1 commit intoswiftlang:masterswiftlang/swift-corelibs-libdispatch:masterfrom

dgrove-oss:fix-swiftc-warningsdgrove-oss/swift-corelibs-libdispatch:fix-swiftc-warningsCopy head branch name to clipboard