Parsed object should be dead

[Dan Eble]

Did something change in the past couple of weeks to make "Parsed object should 
be dead" messages more likely?  Now that I've turned from documentation back to 
development, they seem to be getting in my way much more than they used to.

This stands out:

commit d1be5ec60a058e363835bee60ece6fc61a67c5a9
Author: Han-Wen Nienhuys <hanwenn@gmail.com>
Date:   Sun Jan 24 16:50:19 2021 +0100

    Introduce 'debug-gc-lifetimes option
    
    The debug-gc-assert-parsed-dead feature has been documented, but it is
    really an internal mechanism (it only has effect during garbage
    collection, and has to be coupled with calls to ly:parsed-undead-list!
    in order to do something useful.
    
    Instead, introduce the debug-gc-object-lifetimes option, which
    controls the entire check (ie. the extra GC call, and the printing of
    objects afterwards). For backward compatibility, this feature defaults
    to #t.

I wonder if we could disable this by default.  As a user, I don't like getting 
672 lines of console output when I would have gotten 31 with this option 
disabled.
— 
Dan