vgsp-sema: hold unresolved-operand entries and withhold their releases (ISSUE-0002)

The guest's pma scrub submits vidmem memsets whose operand translations
(client buffer VAs pinned by the scanner) land about a second after the
push. r58 lost those ops to the one-pass skip; r59 showed that retrying
them without deferring the entry's releases corrupts the next client
(the late re-run memset executes after the client passed the release and
refilled the staging buffer).

Hold the entry AND record its decoded releases in per-(device, channel,
entry) slots while any op of the pass is untranslated; apply the recorded
set when the retried decode completes every op, deliver it late on entry
consume, or flush it when the bounded hold (10 s, inside the 25 s CE
grace) expires with the op left skipped as before. Slots are dropped on
session flush and for vanished channels. New opdef=held/applied/expired
counters in the drain line.

0 files changed, 0 insertions, 0 deletions