don't let source-map-support use xhr - 25-75% speed improvement

[lukeapage]

Summary

When jsdom is installed, source-map-support does this:
https://github.com/evanw/node-source-map-support/blob/master/source-map-support.js#L110

Which for me caused a massive slowdown. With this patch my tests go from 99s to 74s to run and an individual test suite 16s to 4s.

Test plan

Jest can only run in node - I am not sure this needs tests?

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at cla@fb.com. Thanks!

[lukeapage]

Will edit changelog soon.

[codecov-io]

Codecov Report

Merging #5045 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #5045   +/-   ##
=======================================
  Coverage   60.74%   60.74%           
=======================================
  Files         198      198           
  Lines        6605     6605           
  Branches        4        4           
=======================================
  Hits         4012     4012           
  Misses       2593     2593

Impacted Files	Coverage Δ
packages/jest-jasmine2/src/index.js	5.97% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0c4399b...d2d1190. Read the comment docs.

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[cpojer]

Wow that's weird. Awesome fix, thanks for sending a PR :)

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.