It works both with trunk or x.y.z versions, resulting in trunk for the
former and x.y for the latter.

Refs #3831

We have various stat counters for the shared memory log (shmlog),
but nothing to give us the number of bytes used (consumed). The
new shm_bytes counter remedies that.
Signed-off-by: Dridi Boukelmoune <dridi.boukelmoune@gmail.com>

According to the GCC manual on -fno-omit-frame-pointer:

> Note that -fno-omit-frame-pointer doesn't guarantee the frame pointer
> is used in all functions.  Several targets always omit the frame
> pointer in leaf functions.

And what is says about -m[no-]omit-leaf-frame-pointer:

> -momit-leaf-frame-pointer
> -mno-omit-leaf-frame-pointer
>
> Omit or keep the frame pointer in leaf functions.  The former behavior
> is the default.

So we should probably prevent both.

Closes #3831

Required for seamless debugging.

Alternatives considered:
- add vext_so_keep debug flag -> overkill

To decide:
- rename to libso_keep / "Keep copied VMOD/VEXT libraries" ?
  (libso to disambiguate from so for socket option)

Create a list of imports, and complain (harmlessly) if the same vmod is imported in multiple versions.

does not apply in varnish-cache, but found useful in a vmod

And rename the "check" parameter to "make_target" to avoid ambiguity.

Better diff with the --word-diff --word-diff-regex=[a-z]+ options.

And lay out the arbitrary selection rule for the sanitizer build.

And lay out the arbitrary selection rule for the 32bit build.

Everyone knows its package manager is APPX.

Manually replaced %% from printf format with %

Added coccinelle patch and applied it.

Indentation polished manually - can we teach spatch our cstyle?

Ref 5e5b442f

spotted by gcc 9.4.0:

	error: format not a string literal and no format arguments
	[-Werror=format-security]

Some of the container images in our continuous integration are stripped
of those commands.

std.now() fills a gap left by the stable time of the now variable in
VCL: Sometimes we need to know the current time after some longer
processing in VCL.

std.timed_call() is intended to measure longer operations in
VCL. std.timestamp() exists already to add accurate measurements to
the log. std.timed_call() is for cases where the duration is required
in VCL, for example to enrich HTTP requests/responses.

I found myself needing this option to incrementally build a query and a
format on a large VSL compressed file. Because of the small nature of
the ncsa output I was working with and the narrow query I was refining,
and the decompression delay, it would take forever to complete this
pipeline:

    zcat '...' | varnishncsa -r - -g request -q '...' -F '...' | head -n 5

With the -k option it happens instantly. Alternatively, it could
probably have worked also with the -u option, but it wouldn't be a
one-liner change, and it would also result in a more complex command:

    zcat '...' | varnishncsa -r - -g request -q '...' -F '...' -k 5
    # vs
    zcat '...' | varnishncsa -r - -g request -q '...' -F '...' -u | head -n 5

The -k option would also generally be useful in "live" mode.

Better diff with the --word-diff --word-diff-regex=. options.