process: add source-map support to stack traces

[bcoe]

This uses SourceMap.js (shipped with V8) and the cache developed in #28960, to add source-map support to stack traces.

How it works:

If you run your program with the flag --source-map-support, and a source-map is found and cached for a file, stack traces are annotated with both the original and transpiled source positions:

Error: goodbye
    at  /Users/bencoe/oss/node-1/test/fixtures/source-map/inline-throw.min.js:1:43
         -> /Users/bencoe/oss/node-1/test/fixtures/source-map/throw.js:8:2
    at  Immediate.<anonymous> (/Users/bencoe/oss/node-1/test/fixtures/source-map/inline-throw.min.js:1:60)
         -> /Users/bencoe/oss/node-1/test/fixtures/source-map/throw.js:8:2
    at  processImmediate (internal/timers.js:439:21)

Providing both the original and transpiled source if possible.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines
• test with source-map generated by uglify.
• test with source-map generated by babel.
• test with source-map generated by TypeScript.
• test with source-map generated by nyc/Istanbul.

This grows out of continuing conversation here.

And relies on #28960, which I would ideally like to land first. (landed).

[benjamingr]

Code LGTM with devsnek's comments addressed. I'll also play with this locally a bit and see if it behaves consistently. Thanks for this this is a big usability improvement in core for a lot of our users!

(Note this will probably have to be semver-major and with a CITGM run because it changes all errors and some libraries parse them)

[bcoe]

@benjamingr do you think a major is necessary, even though someone will opt in with --experimental-source-maps, I'm thinking if we drop the experimental we'd probably just switch to --enable-source-maps and keep it opt in?

Open to other people's thinking on this.

[ljharb]

While behind an experimental flag, I’d expect no changes to precipitate a major.

[joyeecheung]

If it's opt-in via flags I don't think this need to be semver-major. BTW I think it's fine to just use --enable-source-maps from the start with an experimental warning.

[benjamingr]

Sorry for being unclear: I do not think this needs to be major with the flag but I do eventually think Node.js should turn this on by default and that change should be semver-major.

+1 for Joyee's idea of doing --enable-source-maps, I would even take this one step further because I'd like this to be opt-out eventually rather than opt-in and I'd prefer:

--source-maps=true which eventually would be the default and users would be able to opt out with --source-maps=false

[bcoe]

@LinusU I'm wondering if you have any feedback, as we start to build this out; I imagine you've bumped into some interesting edge cases building source-map-support.