See https://github.com/google/packetdrill/commit/47582211690ffc2a7f40c371c19d283b2df26a44#diff-9b9398b17ceeb5025735f4c20d63a3e5L547

used by it.

Sponsored by:	Netflix

Don't check optval in getsockopt() when it call failed.
The value makes no sense.
While there, fix a memomry leak.

This patch is based on work by
Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
It was manually merged, since the patch didn't apply cleanly.
The syscal was also added to the syntax highlighting files for
vim, emacs and bbedit.

When a blocking system call is ongoing, the error message shown was
wrong. It was indicated that a blocking system call is on-going when
the program terminates. This is correct, but hides the error message
which describes why packetdrill is terminating.

Sponsored by:	Netflix

Sponsored by:	Netflix

The thread name is only used for debugging. On Linux this
breaks is_thread_sleeping(), since it assumes that the
process or threadname contains no space. Just don't set
this on Linux, so avoid any problems.

Sponsored by Netflix

Sponsored by Netflix

This is required to support blocking system calls on FreeBSD.
Sponsored by Netflix.

This helps in debugging.