src: enable libm trig functions in V8

[jasnell]

Should provide better performance on some platforms.

                       confidence improvement accuracy (*)   (**)  (***)
util/trig.js n=1000000        ***     37.41 %       ±2.11% ±2.81% ±3.67%

Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 1 comparisons, you can thus
expect the following amount of false-positive results:
  0.05 false positives, when considering a   5% risk acceptance (*, **, ***),
  0.01 false positives, when considering a   1% risk acceptance (**, ***),
  0.00 false positives, when considering a 0.1% risk acceptance (***)

Context: @t3dotgg put together some benchmarks that show the trig functions running in node.js aren't as fast as they could be. We did some digging and think this may help. https://github.com/t3dotgg/cf-vs-vercel-bench/blob/main/vanilla-bench/vercel-edition/api/

There's a possibility this won't work on all platforms/archs so running some tests in CI to verify first. Appears to be fine in CI!

/cc @nodejs/v8

[nodejs-github-bot]

Review requested:

• @nodejs/gyp
• @nodejs/performance

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/69607/ 💛

[devsnek]

just a note of interest... several years ago I tried applying libm optimizations to some operations in V8 (though, not the trig functions) and we eventually found the output to be bad enough in certain cases to necessitate reverting it.

[mcollina]

lgtm

[targos]

I don't oppose to the idea but I don't see how this change can have any effect, given that the build flag is not implemented in the GYP files: