Cleverness of GC Scanning

[via Digitalmars-d]

Is the current Phobos GC smart enough to *not* scan GC-allocated 
arrays when the elements don't contain any indirections 
(references/pointers).

If not how difficult would it be to fix this? There are bunch of 
traits in Phobos that check for this. If these were moved to 
druntime I guess they could be reused in GC-implementation, right?