Revert canonical flag in allocate
Revert canonical flag in allocate

Initially I meant to ensure the allocator gave back sequential memory in
segment0, but ended up using a hope+validate approach. Given this
approach, modification of this function adds useless complexity.

hntrmrrs/capnproto,jparyani/capnproto,pjulien/capnproto,pjulien/capnproto,mrdomino/capnproto,hntrmrrs/capnproto,jparyani/capnproto,mrdomino/capnproto,mologie/capnproto,mologie/capnproto,mrdomino/capnproto,mologie/capnproto,jparyani/capnproto,pjulien/capnproto,hntrmrrs/capnproto