Change the default handling for SIGPIPE to pass/,no-stop/no-notify.
Change the default handling for SIGPIPE to pass/,no-stop/no-notify.

Most of the time SIGPIPE is just annoying, and so we should
pass it on silently it by default.

<rdar://problem/39359145>


git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@344418 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb