Log Message:
lang/nodejs8: Update to 8.12.0.

- async_hooks:
  - rename PromiseWrap.parentId
  - remove runtime deprecation
  - deprecate unsafe emit{Before,After}
- cluster:
  - add cwd to cluster.settings
  - support windowsHide option for workers
- crypto:
  - allow passing null as IV unless required
- deps:
  - upgrade npm to 6.4.1
  - upgrade libuv to 1.19.2
  - Upgrade node-inspect to 1.11.5
- fs,net:
  - support as and as+ flags in stringToFlags()
  - emit 'ready' for fs streams and sockets
- http, http2:
  - add options to http.createServer()
  - add 103 Early Hints status code
  - add http fallback options to .createServer
- n-api:
  - take n-api out of experimental
- perf_hooks:
  - add warning when too many entries in the timeline
- src:
  - add public API for managing NodePlatform
  - allow --perf-(basic-)?prof in NODE\_OPTIONS
  - node internals' postmortem metadata
- tls:
  - expose Finished messages in TLSSocket
- trace_events:
  - add file pattern cli option
- util:
  - implement util.getSystemErrorName()