doc,test: args to `buffer.copy` can be Uint8Arrays
This was semi-overlooked in https://github.com/nodejs/node/pull/10236 because it always worked and didn’t need additional changes.
Ref: https://github.com/nodejs/node/pull/10236
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
buffer