Polyfill: Check that time is not start-of-day in ToTemporalInstant

[catamorphism]

The TemporalInstantString production requires a Time, so time will never be start-of-day in this code.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.90%. Comparing base (03f9057) to head (928027c).
⚠️ Report is 41 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3230      +/-   ##
==========================================
+ Coverage   96.75%   97.90%   +1.14%     
==========================================
  Files          22       22              
  Lines       10398    10365      -33     
  Branches     1859     1815      -44     
==========================================
+ Hits        10061    10148      +87     
+ Misses        289      198      -91     
+ Partials       48       19      -29     

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[ptomato]

Looks like we can make the same change in the spec text, in ToTemporalInstant step 6.

[catamorphism]

Looks like we can make the same change in the spec text, in ToTemporalInstant step 6.

Done in 4392a0a

[ptomato]

👍