We don't actually need the full analysis to compute exports. This can
break some task cycles, and might theoretically improve task latency.

The CPU time appears to be marginally higher (but not statistically
significant), but no impact on overall build time:
```
* c4fdcc2 - (14 hours ago) compute exports before final_read_hint() - Niklas Mischkulnig (origin/mischnic/get-exports-without-analyze, mischnic/get-exports-without-analyze)

pnpm next build --experimental-build-mode=compile  378.10s user 58.28s system 760% cpu 57.411 total
pnpm next build --experimental-build-mode=compile  383.64s user 60.32s system 738% cpu 1:00.10 total
pnpm next build --experimental-build-mode=compile  378.70s user 55.65s system 718% cpu 1:00.41 total

* 8ddc1cd - (38 minutes ago) Use OIDC for CodSpeed (#93059) - Niklas Mischkulnig (origin/canary, origin/HEAD, canary)

pnpm next build --experimental-build-mode=compile  376.95s user 58.30s system 755% cpu 57.597 total
pnpm next build --experimental-build-mode=compile  375.85s user 61.75s system 738% cpu 59.230 total
pnpm next build --experimental-build-mode=compile  377.75s user 63.00s system 729% cpu 1:00.39 total
```

Currently doesn't have a measureable performance impact.

Attempt the cheap downcast first and only do the ident reading and
comparison in the uncommon case