src: tag v8 aligned pointer slots with embedder data type tags

[legendecas]

Fixes: #60589

[nodejs-github-bot]

Review requested:

• @nodejs/net
• @nodejs/realm
• @nodejs/startup

[codecov]

Codecov Report

❌ Patch coverage is 91.17647% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.54%. Comparing base (b4b1413) to head (5ff1880).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
src/js_udp_wrap.cc	0.00%	1 Missing ⚠️
src/node_snapshotable.cc	80.00%	0 Missing and 1 partial ⚠️
src/stream_base-inl.h	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #60602      +/-   ##
==========================================
- Coverage   88.56%   88.54%   -0.03%     
==========================================
  Files         704      704              
  Lines      208077   208085       +8     
  Branches    40084    40082       -2     
==========================================
- Hits       184289   184253      -36     
- Misses      15826    15867      +41     
- Partials     7962     7965       +3     

Files with missing lines	Coverage Δ
src/base_object-inl.h	82.70% <100.00%> (+0.75%)	⬆️
src/base_object.cc	84.31% <100.00%> (-0.99%)	⬇️
src/base_object.h	100.00% <ø> (ø)
src/cppgc_helpers-inl.h	84.00% <100.00%> (ø)
src/env-inl.h	94.45% <100.00%> (-0.02%)	⬇️
src/env.cc	85.07% <100.00%> (-0.38%)	⬇️
src/histogram.cc	78.96% <100.00%> (-0.06%)	⬇️
src/node_context_data.h	83.33% <100.00%> (ø)
src/node_contextify.cc	81.78% <ø> (-0.09%)	⬇️
src/node_process_methods.cc	88.69% <100.00%> (ø)
... and 5 more

... and 29 files with indirect coverage changes

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[joyeecheung]

RSLGTM. I feel that it'd be nicer to add a method to BaseObject that allows setting arbitrary slot with the tag so that we don't have to repeat the default argument in all its subclasses, but that can be a followup

[legendecas]

I feel that it'd be nicer to add a method to BaseObject that allows setting arbitrary slot with the tag so that we don't have to repeat the default argument in all its subclasses, but that can be a followup.

Many of the changed lines in this PR are not in the subclasses of BaseObject. We might need a standalone helper util if it makes sense.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70069/