roq: use reg to keep track of the number of valid entries

dpq: use reg to keep track of the number of valid entries

Coverage

this greatly accelerates compilation.

Fix source d uncached get bypass

redirect: add RedirectLevel to simplify flush logic

emu: change exit code

This works for linux-hello which never stops.
Now, we can stop emu with sigint and still get a valid coverage result.

difftest: support store commits (to dcache)

brq: don't store brUpdate.pc and use uop.cf.pc

Ifu timing

brq, lsq: fix enqueue logic

roq: wrap commitInfo in RoqDataModule