assign_pmc broken for pir subclasses?

[coke]

.sub main

 $P1 = new 'Hash'
 .local pmc undef
 undef = new 'Undef'
 assign $P1, undef
 $S0 = typeof $P1
 say $S0

 $P1 = get_class 'Hash'
 $P2 = subclass $P1, 'myHash'

 $P1 = new 'myHash'
 .local pmc undef
 undef = new 'Undef'
 assign $P1, undef
 $S0 = typeof $P1
 say $S0

.end

this prints:

Undef
myHash

but I expect it to print

Undef
Undef

- this is blocking partcl.

[coke]

(This is no longer blocking partcl, as using 'copy' instead of 'assign' produces the desired results.)

This should probably still be resolved, however.