[POSIX] Workaround for old glibc bug in posix_spawn_file_actions_addopen
[POSIX] Workaround for old glibc bug in posix_spawn_file_actions_addopen

posix_spawn_file_actions_addopen should copy its path argument by
specification but does't do that.
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=89e435f3559c53084498e9baad22172b64429362

sschiau/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,haskellswift/swift-package-manager,vmanot/swift-package-manager,vmanot/swift-package-manager,haskellswift/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager