This is an intermediate fix to handle sends to sockets shut down by the
peer already. A final fix in the libc would add support for the
MSG_NOSIGNAL send flag, generate SIGPIPE, and return the expected EINTR.
Then this patch is no longer required.
This commit also drops the obsolete patch for missing
sysconf(_SC_NPROCESSORS_ONLN), which is now part of libc.