RFR: 8184795: [MVT] non constant method handles can cause allocations in method handle combinators

[Roland Westrelin]

>> http://cr.openjdk.java.net/~roland/8184795/webrev.01/
>
> Thanks for making the changes, this looks good to me.
>
> All tests pass on JPRT (I haven't seen the spurious GC crashes again).

Thanks!

Roland.