perf(core): reduce native callback snapshot overhead (#35121)
## Summary
This reduces startup snapshot deserialization overhead from native
callback function shapes.
The stack does three things:
- creates native accessor callbacks with `ConstructorBehavior::Throw`,
avoiding useless accessor `.prototype` graphs
- uses direct V8 functions for snapshotted top-level ops instead of
FunctionTemplates by default
- adds an explicit `#[op2(constructable)]` opt-in for top-level ops that
must preserve a public JS function prototype/constructor shape
## Snapshot Size
Measured with debug builds:
```sh
deno run --v8-flags=--profile-deserialization empty.js
```
Summing the three `Deserializing ... (N bytes)` rows, excluding the
final `Serializing to ...` row:
| build | total deserialized bytes | delta |
| --- | ---: | ---: |
| `main@upstream` | 4,768,928 | - |
| this PR | 4,466,352 | -302,576 bytes |
That is a 6.34% reduction in the deserialized snapshot byte total for
this measurement.
Breakdown:
| section | `main@upstream` | this PR | delta |
| --- | ---: | ---: | ---: |
| read-only space | 991,144 | 991,144 | 0 |
| isolate | 2,561,136 | 2,518,976 | -42,160 |
| context #2 | 1,216,648 | 956,232 | -260,416 |
Saved local binaries used for the comparison:
- `/tmp/deno-accessor-snapshot-binaries/deno-baseline-main-upstream`
-
`/tmp/deno-accessor-snapshot-binaries/deno-current-constructable-stack`
## Validation
```sh
cargo test -p deno_core_testing resource_test
cargo test -p deno_ops op2::tests
cargo check -p deno_core -p deno_core_testing -p deno_ops
```
