Ref: https://github.com/varnishcache/varnish-cache/commit/5450550906d0809dfc21ae9d3a5b14446c1809d4

Ref:    d67993451bda7eeb7c0ea3c5528a8353f283a190

This reverts commit 5829411d.

ref: 0c74d1b99f1f43fc99725fe14322760afa7858ee

Ref: e8985f22711fe9a342b27a10052ae3655f64435c

ref https://github.com/varnishcache/varnish-cache/issues/2840

The reason is the same as for
https://github.com/varnishcache/varnish-cache/issues/2708 :

VRT_priv_task may now return NULL for out-of-workspace errors, see
https://github.com/varnishcache/varnish-cache/commit/de2b431086a13b243dc8b3e71cd8697db1df2c7f

A Host: header is now added always, which accounts for another
17 bytes for connections to 127.0.0.1

The purpose of these tests was to ensure that vmod_blobcode works identical
to shard.key(). Now that the latter has been changed to only support SHA256,
we need to remove out tests for custom hashes.

Ref: https://github.com/varnishcache/varnish-cache/pull/2558

varnish-cache commit 51176640603b123a38b49ae271cb9c9de9df1d28

Also move tests to vcl_recv for better visibility because VRT_fail
from vcl_synth just closes the connection