fs: fix writev UNKNOWN on large buffers

[themuuln]

Fixes #40779

What changed

fs.writev, fs.writevSync, and FileHandle.writev now validate total byteLength before the syscall. If the sum exceeds kIoMaxLength (2147483647), they throw ERR_OUT_OF_RANGE with the received length instead of letting libuv wrap to -2147483648 and surface as UNKNOWN.

• lib/fs.js: added loop + ERR_OUT_OF_RANGE.HideStackFramesError in writev and writevSync
• lib/internal/fs/promises.js: same check in FileHandle.writev

This matches the fix for fs.write in c4e7dca, which validated length against kIoMaxLength before uv_fs_write.

Why

Repro from the issue:

const fd = fs.openSync("./test.dat", fs.constants.O_WRONLY | fs.constants.O_CREAT);
fs.writevSync(fd, [Buffer.alloc(0x7FFFFFFF + 1)], 0);
// before: throws { code: 'UNKNOWN', errno: -2147483648 }
// after: throws { code: 'ERR_OUT_OF_RANGE', message: 'The value of "length" is out of range. It must be <= 2147483647. Received 2147483648' }

Several small buffers that sum past 2 GiB hit the same wrap. The new check catches the sum early and gives an actionable error.

Tests

Added test/parallel/test-fs-writev-buffer-large.js, modeled on test-fs-write-buffer-large.js:

• writevSync throws ERR_OUT_OF_RANGE for [bigBuffer] and [bigBuffer, small]
• writev (callback) throws synchronously, callback never called
• FileHandle.writev rejects with ERR_OUT_OF_RANGE; [] still returns bytesWritten: 0

The test skips on 32-bit and when allocation fails (Array buffer allocation failed).

Verification locally:

• npx eslint lib/fs.js lib/internal/fs/promises.js test/parallel/test-fs-writev-buffer-large.js — no errors
• Inspected kIoMaxLength imports and validateBufferArray order

Refs: c4e7dca

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.01%. Comparing base (f9ab994) to head (249b825).
⚠️ Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65736      +/-   ##
==========================================
- Coverage   90.07%   90.01%   -0.07%     
==========================================
  Files         754      755       +1     
  Lines      256395   257310     +915     
  Branches    48494    48784     +290     
==========================================
+ Hits       230947   231611     +664     
- Misses      16563    16793     +230     
- Partials     8885     8906      +21     

Files with missing lines	Coverage Δ
lib/fs.js	98.44% <100.00%> (+<0.01%)	⬆️
lib/internal/fs/promises.js	92.32% <100.00%> (+0.02%)	⬆️

... and 44 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.