[gclist] Experience with conservative GC sought

[Jim Blandy]

My present SCWM heap has 40k objects allocated, of 98k available.  One
object is an eight-byte cell, which may point to additional storage if
it represents a string, a vector, etc.  Only the cells are relevant to
conservative GC issues.  So it's small.  And I'm not doing heavy work
with it.

My Emacs heap has, in comparison, ~224k objects.

David Love suggested that I simply retrofit Emacs with a GJC-style
collector and see what happens.  This seems quite doable.  Deciding
exactly what to instrument would be interesting, though.