Editorial: Split total() code path out of RoundRelativeDuration

In #2758 we kept the code paths for Duration.p.round() and
Duration.p.total() the same. However, it is actually simpler to separate
them in most places, except for NudgeToCalendarUnit.

- Splits TotalRelativeDuration out of RoundRelativeDuration
- Splits TotalTimeDuration out of RoundTimeDuration
- Splits DifferenceZonedDateTimeWithTotal out of
  DifferenceZonedDateTimeWithRounding
- Splits DifferencePlainDateTimeWithTotal out of
  DifferencePlainDateTimeWithRounding
- Removes [[Total]] field from Nudge Result Record
- Changes NudgeToCalendarUnit to return a record of { [[NudgeResult]],
  [[Total]] }

Closes: #2947

polyfill/lib/duration.mjs

@@ -10,7 +10,6 @@ import {
 
   // class static functions and methods
   MathAbs,
-  NumberIsNaN,
   ObjectCreate,
   ObjectDefineProperty,
 
@@ -236,7 +235,7 @@ export class Duration {
       const calendar = GetSlot(zonedRelativeTo, CALENDAR);
       const relativeEpochNs = GetSlot(zonedRelativeTo, EPOCHNANOSECONDS);
       const targetEpochNs = ES.AddZonedDateTime(relativeEpochNs, timeZone, calendar, duration);
-      ({ duration } = ES.DifferenceZonedDateTimeWithRounding(
+      duration = ES.DifferenceZonedDateTimeWithRounding(
         relativeEpochNs,
         targetEpochNs,
         timeZone,
@@ -245,7 +244,7 @@ export class Duration {
         roundingIncrement,
         smallestUnit,
         roundingMode
-      ));
+      );
       if (ES.TemporalUnitCategory(largestUnit) === 'date') largestUnit = 'hour';
       return ES.UnnormalizeDuration(duration, largestUnit);
     }
@@ -260,7 +259,7 @@ export class Duration {
       const dateDuration = ES.AdjustDateDurationRecord(duration.date, targetTime.deltaDays);
       const targetDate = ES.CalendarDateAdd(calendar, isoRelativeToDate, dateDuration, 'constrain');
 
-      ({ duration } = ES.DifferencePlainDateTimeWithRounding(
+      duration = ES.DifferencePlainDateTimeWithRounding(
         isoRelativeToDate.year,
         isoRelativeToDate.month,
         isoRelativeToDate.day,
@@ -284,7 +283,7 @@ export class Duration {
         roundingIncrement,
         smallestUnit,
         roundingMode
-      ));
+      );
       return ES.UnnormalizeDuration(duration, largestUnit);
     }
 
@@ -297,7 +296,7 @@ export class Duration {
     }
     assert(!ES.IsCalendarUnit(smallestUnit), 'smallestUnit was larger than largestUnit');
     let duration = ES.NormalizeDurationWith24HourDays(this);
-    ({ duration } = ES.RoundTimeDuration(duration, roundingIncrement, smallestUnit, roundingMode));
+    duration = ES.RoundTimeDuration(duration, roundingIncrement, smallestUnit, roundingMode);
     return ES.UnnormalizeDuration(duration, largestUnit);
   }
   total(totalOf) {
@@ -320,18 +319,7 @@ export class Duration {
       const calendar = GetSlot(zonedRelativeTo, CALENDAR);
       const relativeEpochNs = GetSlot(zonedRelativeTo, EPOCHNANOSECONDS);
       const targetEpochNs = ES.AddZonedDateTime(relativeEpochNs, timeZone, calendar, duration);
-      const { total } = ES.DifferenceZonedDateTimeWithRounding(
-        relativeEpochNs,
-        targetEpochNs,
-        timeZone,
-        calendar,
-        unit,
-        1,
-        unit,
-        'trunc'
-      );
-      assert(!NumberIsNaN(total), 'total went through NudgeToZonedTime code path');
-      return total;
+      return ES.DifferenceZonedDateTimeWithTotal(relativeEpochNs, targetEpochNs, timeZone, calendar, unit);
     }
 
     if (plainRelativeTo) {
@@ -344,7 +332,7 @@ export class Duration {
       const dateDuration = ES.AdjustDateDurationRecord(duration.date, targetTime.deltaDays);
       const targetDate = ES.CalendarDateAdd(calendar, isoRelativeToDate, dateDuration, 'constrain');
 
-      const { total } = ES.DifferencePlainDateTimeWithRounding(
+      return ES.DifferencePlainDateTimeWithTotal(
         isoRelativeToDate.year,
         isoRelativeToDate.month,
         isoRelativeToDate.day,
@@ -364,13 +352,8 @@ export class Duration {
         targetTime.microsecond,
         targetTime.nanosecond,
         calendar,
-        unit,
-        1,
-        unit,
-        'trunc'
+        unit
       );
-      assert(!NumberIsNaN(total), 'total went through NudgeToZonedTime code path');
-      return total;
     }
 
     // No reference date to calculate difference relative to
@@ -382,8 +365,7 @@ export class Duration {
       throw new RangeErrorCtor(`a starting point is required for ${unit}s total`);
     }
     const duration = ES.NormalizeDurationWith24HourDays(this);
-    const { total } = ES.RoundTimeDuration(duration, 1, unit, 'trunc');
-    return total;
+    return ES.TotalTimeDuration(duration.norm, unit);
   }
   toString(options = undefined) {
     if (!ES.IsTemporalDuration(this)) throw new TypeErrorCtor('invalid receiver');
@@ -400,7 +382,7 @@ export class Duration {
 
     const largestUnit = ES.DefaultTemporalLargestUnit(this);
     let duration = ES.NormalizeDuration(this);
-    ({ duration } = ES.RoundTimeDuration(duration, increment, unit, roundingMode));
+    duration = ES.RoundTimeDuration(duration, increment, unit, roundingMode);
     const roundedDuration = ES.UnnormalizeDuration(duration, ES.LargerOfTwoTemporalUnits(largestUnit, 'second'));
     return ES.TemporalDurationToString(roundedDuration, precision);
   }