Add Date.prototype.toTemporalInstant()

[Schweinepriester]

• https://tc39.es/proposal-temporal/docs/cookbook.html#temporal-types-from-legacy-date
• Better conversion between legacy Date and Temporal tc39/proposal-temporal#515 (comment)
• Safari:
  • Shipped in TP 137: https://webkit.org/blog/12156/release-notes-for-safari-technology-preview-137/
  • Issue: https://bugs.webkit.org/show_bug.cgi?id=232075
• Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1732145

I think it's likely that this will come via MDN or eventually be defined as part of https://caniuse.com/temporal, but keeping track for now :)

[Schweinepriester]

Available via MDN by now: https://caniuse.com/mdn-javascript_builtins_date_totemporalinstant

Closing as such…