Non-UTF-8 env vars  #16961

• Version: v8.8.1
• Platform: Linux daurn-z170 4.13.7-1-ARCH deps: update openssl to 1.0.1j #1 SMP PREEMPT Sat Oct 14 20:13:26 CEST 2017 x86_64 GNU/Linux
• Subsystem: process

Node.js doesn't seem to have a way to read environment variables that aren't valid unicode. For both keys and values. e.g.

$ env -i $'F\xa5B=BAR' node -e 'console.log(process.env)' 
{ 'F�B': undefined }
$ env -i $'FOO=B\xa5R' node -e 'console.log(process.env.FOO.codePointAt(1))'
65533