[pmo] Update the memory use collector for ownership.
This is technically a NFC commit. The changes are:
1. When we scalarize loads/stores, we need to not just use unqualified
loads/stores. Instead we need to use the createTrivial{Load,Store}Or APIs. In
OSSA mode, this will propagate through the original ownership qualifier if the
sub-type is non-trivial, but if the sub-type is non-trivial will change the
qualifier to trivial. Today when the pass runs without ownership nothing is
changed since I am passing in the "supports unqualified" flag to the
createTrivial{Load,Store}Or API so that we just create an unqualified memop if
we are passed in an unqualified memop. Once we fully move pmo to ownership, this
flag will be removed and we will assert.
2. The container walker is taught about copy_value, destroy_value. Specifically,
we teach the walker how to recursively look through copy_values during the walk
and to treat a destroy_value of the box like a strong_release,
release_value. Since destroy_value, copy_value only exist in [ossa] today, this
is also NFC.
