DDT Symbols etc.

[RLB at MIT-MC (Richard L. Bryan)]

Given the presence in much code of something like
(or (getddtsym 'T) (valret '|^W:sl sys:ts l/
:vp |))
I propose instead (yet) another status/sstatus option pair:
(status ddtsyms) returns T if the superior claims to be a DDT and has 
symbols loaded;
(sstatus ddtsyms) returns falsity if the superior is not a DDT, else
returns T if the DDT has symbols loaded, else requests the DDT to load symbols
**from the correct SYS:PURQIO nnn** or wherever and returns T if that was 
successful.  Alternatively, this could set some flag for GETDDTSYM which
would cause it to load symbols if necessary.

The advantage of all this is that symbols could be guaranteed to be loaded
from the 'right place' even in the presence of hacking file load defaults,
etc. Hopefully it could even work in the presence of multiple levels of
pdumping, although this would require more careful thought than I am putting
into it now.