b4 am partial-re-roll vs reviewed-by

[Dan Williams <dan.j.williams@intel.com>]

Hi,

I notice that:

b4 am 163225205828.3038145.6831131648369404859.stgit@dwillia2-desk3.amr.corp.intel.com

...warns about a case where I manually replied with a reviewed-by tag
of someone else which is a great feature.

The bit of magic I was also hoping for it to notice is that [PATCH v4
17/21] picked up a reviewed-by with a note that said effectively "if
you fix this, then apply my reviewed-by":

https://lore.kernel.org/r/20210910105313.00006408@Huawei.com

I then neglected to manually add that tag when sending v5:

https://lore.kernel.org/r/163164680798.2831381.838684634806668012.stgit@dwillia2-desk3.amr.corp.intel.com

It would increase b4's already high levels of usefulness if similar to
the -S warning there was a warning of "vX picked up a reviewed-by,
carry that forward by re-running with <option foo>". Sometimes it's an
oversight to miss a previous review tag, and sometimes it is
deliberate that the submitter believes that previous review is
invalidated by the new submission.

No worries if this does not cleanly fit into the b4 series assembly engine.