esm: implement import.meta.main

[Lordfirespeed]

Implements #57226

This PR supersedes #32223

Fixes: #57226

[nodejs-github-bot]

Review requested:

• @nodejs/loaders

[Lordfirespeed]

@ljharb I would appreciate your review on this r.e. performance - I am particularly concerned about my changes in lib/internal/modules/esm/translators.js, since I'm not familiar with implications of assignment to a JS object associated with a native object.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.24%. Comparing base (ada4abf) to head (80e167a).
Report is 49 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #57804      +/-   ##
==========================================
+ Coverage   90.21%   90.24%   +0.03%     
==========================================
  Files         630      630              
  Lines      185518   185680     +162     
  Branches    36383    36398      +15     
==========================================
+ Hits       167360   167573     +213     
+ Misses      11033    11000      -33     
+ Partials     7125     7107      -18     

Files with missing lines	Coverage Δ
lib/internal/modules/esm/initialize_import_meta.js	100.00% <100.00%> (ø)
lib/internal/modules/esm/translators.js	91.59% <100.00%> (+0.01%)	⬆️
lib/internal/modules/esm/utils.js	98.93% <100.00%> (+0.02%)	⬆️

... and 46 files with indirect coverage changes

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[Lordfirespeed]

@ljharb I've moved the assignment into compileSourceTextModule, but I'm a bit confused

I think I can see where the cache is populated, but not where it is hit in compileSourceTextModule (unless it's in CPP?)
That leads me to think the cache gets hit at some point before the standard moduleStrategy function is used, which would mean moving the assignment either has no effect or is detrimental.

What am I missing?

[Lordfirespeed]

I think CI should pass now. make -j$(nproc) test is passing locally.

[Lordfirespeed]

I checked locally, it seems the test no longer fails with unusual character names using a relative import path.