doc: mark accessing IPC channel fd as undefined
Adds note that accessing the fd of the IPC channel in any other way than process.send
, or using the IPC channel with child processes that is not Node.js is undefined.
This adds to what was done in https://github.com/nodejs/node/pull/17460
Fixes: https://github.com/nodejs/node/issues/16491
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
docs