build,win: fail fast in vcbuild without cargo

[vedchaudhari]

If Rust isn't installed, vcbuild.bat doesn't catch it. The build runs for a long time and then fails with:

error MSB8066: Custom build for 'Cargo.toml' exited with code 1. [...\deps\crates\node_crates.vcxproj]

There's already a cargo/rustc check in configure.py, but on Windows check_compiler() returns before it gets there (L1630-L1646, L1670-L1690), so Temporal stays on and cargo_build.py fails when it tries to run cargo.

This adds a small tools/msvs/find_cargo.cmd (similar to find_nasm.cmd) and calls it from vcbuild.bat. It looks for cargo the same way cargo_build.py does: CARGO, then PATH, then %USERPROFILE%\.cargo\bin. Without Rust, the build now stops right away:

Looking for cargo
Could not find cargo, install the Rust toolchain. See BUILDING.md.

The check is skipped for nobuild, clean, and when --v8-disable-temporal-support or --shared-temporal_capi is passed, same as configure.py.

Tested on Windows 11 with and without Rust on PATH, with CARGO set to a full path, and with rustup in %USERPROFILE%\.cargo\bin.

Note : it only checks that cargo exists, not rustc or the versions (configure.py only warns about old versions on other platforms). Also, BUILDING.md says a missing cargo disables Temporal, which isn't the case on Windows. I can fix that in a follow-up.

Fixes: #66848
Refs: #63451

Assisted-by: Claude Code. I reproduced the issue, reviewed the change, and tested it with and without Rust on PATH myself.

[MikeMcC399]

Thanks @vedchaudhari !

I cross-checked against my original issue #66848

Rust Toolchain installed

I checked with the following installed on Windows 11 26H2, running .\vcbuild.bat in PowerShell:

• rustc 1.99.1
• cargo 1.99.1

build and smoke-test were successful.

Release\node -e "console.log('Hello from Node.js', process.version)"
Hello from Node.js v27.0.0-pre

Rust Toolchain uninstalled

Executing rustup self uninstall (uninstalls rustc & cargo), confirms fast failure:

 .\vcbuild.bat
Looking for Python
Python found in C:\Users\mikem\AppData\Local\Microsoft\WindowsApps\\python.exe
Python 3.15.0
Looking for NASM
Looking for cargo
Could not find cargo, install the Rust toolchain. See BUILDING.md.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/78509/