buffer: fix creating from zero-length ArrayBuffer
Checklist
-
tests and code linting passes -
a test and/or benchmark is included -
the commit message follows commit guidelines
Affected core subsystem(s)
buffer
Description of change
Fixes regression introduced in https://github.com/nodejs/node/commit/85ab4a5f1281c4e1dd06450ac7bd3250326267fa where creating a new Buffer from an empty ArrayBuffer would fail.
Initially found in #6893.
cc @trevnorris @addaleax @ChALkeR