fix(v8): passing the InnerTrap::User through the v8 backend

[marxin]

Fixes: #6540

[Copilot]

Pull request overview

This PR addresses #6540 by improving how the V8 backend propagates “user” traps (e.g., WASI proc_exit) so that ExitCode::0 is treated as a successful run instead of being surfaced as a misleading runtime error.

Changes:

• Add a CLI integration test to assert wasmer run --v8 treats proc_exit(0) as success.
• Adjust V8 trap serialization/deserialization to round-trip InnerTrap::User through the wasm-c-api trap message.
• Advertise V8 exception-handling support in the engine feature set and add v8 to VS Code rust-analyzer features.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/integration/cli/tests/run.rs	Adds an integration test ensuring proc_exit(0) is considered success under V8.
lib/api/src/backend/v8/error.rs	Updates user-trap encoding/decoding in trap messages for V8.
lib/api/src/backend/v8/entities/engine.rs	Enables exceptions in V8’s reported supported features.
.vscode/settings.json	Adds the v8 feature to rust-analyzer’s enabled feature list.

Comments suppressed due to low confidence (1)

lib/api/src/backend/v8/error.rs:106

• Decoding user traps via message.split_once("🐛") is too permissive and can misclassify unrelated trap messages that happen to contain the marker. Because the code then unwrap()s the hex parse and does ptr::read on the resulting address, a malformed/attacker-controlled message can cause a panic or UB. Tighten the detection (e.g., require an expected prefix like "Exception: 🐛"/"Error: 🐛" and ensure the remainder is exactly a hex pointer token), and handle parse failures by falling back to InnerTrap::CApi instead of panicking/reading an arbitrary pointer.

        if let Some((_, ptr_str)) = message.split_once("🐛") {
            let ptr: Box<dyn Error + Send + Sync + 'static> = unsafe {
                let r = ptr_str.trim_start_matches("0x");
                std::ptr::read(usize::from_str_radix(r, 16).unwrap()
                    as *const Box<dyn Error + Send + Sync + 'static>)

[syrusakbary]

Nice!