Can't put running Node process into debug mode

[roblourens]

nodejs/node#8464

[auchenberg]

This is now scheduled to landing in Node 8.x.x

nodejs/diagnostics#76

[hybrist]

This is the exact change in node itself required for this feature: nodejs/node#11431

[auchenberg]

Landed in Node. No longer blocked.

[auchenberg]

Validated over the weekend with Node nightly. Prototyped in: https://github.com/auchenberg/debug-tunnel/blob/master/index.js#L34

[roblourens]

Discussion about this in microsoft/vscode#25036 - not sure I'll get to it in May, though.