[perl #41825] [BUG] morph vtable override not working in PIR

[Andrew Whitworth via RT]

Okay, I've committed a variant of my patch in r35599, but I've run into
some issues while trying to test this. The morph VTABLE interface takes
an INTVAL which represents the PMC type to morph to. This is the value
that's passed to the morph subroutine. However, there's no easy way
(that I know of) to work with these numbers from PIR. For instance, you
can't create a new PMC of that type from the number, you can't convert
that number to the stringified name of the PMC, you can find out what
the type number is of an existing class, etc. 

I think there are two options to fix this:
1) Add some opcodes such as "typename_s_i" and "typenumber_i_s" that
would convert between the string name of the PMC and the given type
number or
2) Change src/pmc/object.pmc:morph() to pass the stringified name to the
PIR override instead of the INTVAL type number.

I like the second one the best since type numbers may change internally
and we don't want people to be relying on them for other purposes.
However, then the morph vtable override in PIR will take a different
parameter list from the C version of the VTABLE interface, which might
get confusing.

Any suggestions?


-- 
Andrew Whitworth
a.k.a Whiteknight