`crash-fuzz.js` aborted with "harness error: MongoServerError: ns not found"
whenever the surviving prefix contained no write that created the collection --
a kill during the first in-flight command on a fresh log. `listIndexes` on a
missing namespace is NamespaceNotFound, which is what real MongoDB answers too,
so the server was right and the harness treated a legitimate state as its own
failure. Worse, it aborted the run instead of verifying that state, which is
exactly the state worth verifying.
Reproduces with `--seed 1234 --rounds 60` and is why seeded runs were unusable;
`--heavy` happened to miss it. Confirmed against the previous commit before
changing anything, so it is the harness and not the engine.
Both seeds now pass 60 cycles.
Aleksey Shakhmatov
a9f625f82a