coverage: make coverage work for Node.js

[bcoe]

This pull request gets coverage working for Node.js' own internal libraries, I've:

• moved enabling coverage to earlier in the bootstrap process, so that it loads before any other JavaScript dependencies .
• I've switched to using the binding directly, to avoid loading JS dependencies.
• coverage now turns off async hooks before writing, which prevents a bunch of test failures.
• I've updated a few other tests that failed under coverage.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[nodejs-github-bot]

@bcoe build started: https://ci.nodejs.org/blue/organizations/jenkins/node-test-pull-request-lite-pipeline/detail/node-test-pull-request-lite-pipeline/1402/pipeline

[bcoe]

CC: @nodejs/testing

[bcoe]

build: https://ci.nodejs.org/job/node-test-pull-request/18190/

[bcoe]

landed in 4df8c26

[Trott]

Force pushed out. No metadata, 'coverage' is not a valid subsystem.

[Trott]

Commits were landed since the last CI run, so running CI again: https://ci.nodejs.org/job/node-test-pull-request/18321/

[Trott]

(I'll re-land this once CI is good.)

[Trott]

(Also: One more data point for a commit queue!!! People who land commits once in a while shouldn't have to remember/re-learn the process!)

[refack]

Big commit-queue fan here, but node-core-utils is so usful motivation has gone down.

[Trott]

Landed in 616fac9

[bcoe]

sorry about that, I used git node to land, but forgot that I still needed to amend the message if it’s one commit to add meta information (was thinking this was magic).

[joyeecheung]

So I am thinking...what if we implement a git node land --push or something instead of asking people to git push..? (That must be explicitly run by users even if there is only one commit of course, so there is more room for manual validation...but it at least allow more validation than a bare git push at the end and is more flexible than the pre-push hook)

[refack]

git node land --push

Personally I'm not a big fan of the -- flags. Maybe have --final prompt for user input:

$ git node land NJILK ... Would you like to push upstream now. If you do please type NJILK > NJILK git push usptream :tada: 

[joyeecheung]

@refack

Personally I'm not a big fan of the -- flags

I don't really like them either, but couldn't think of anything better :(

Would you like to push upstream now. If you do please type NJILK

Sounds like a good idea to me, although what does NJILK mean?

EDIT: oh, the PR ID?

[refack]

Sounds like a good idea to me, although what does NJILK mean?

the PR_ID

[refack]

See: nodejs/node-core-utils#299

[codebytere]

@bcoe do you think this is a candidate for backporting to v10.x?