implement bufferToString?

[randrrandr1]

Hello!
How about this performance improvement?
nodejs/performance#16

https://github.com/nodejs/node/pull/45562/files#diff-81f77f34c4f5b8cc35f1a506808b94e2a281f3341c0f1a38ef2b8a8ba730b22bR523

[cjihrig]

It looks like that is specific to the Node.js Buffer, which does not exist in Deno. If it ends up in Node, we could add it to Deno's Node compatibility code, but that is implemented in JS, not C++, so it might not lead to much benefit other than compatibility.