Implement check for negative day length in ZonedDateTime.round

This is the corresponding polyfill change to the spec change made in
tc39/proposal-temporal#2261

UPSTREAM_COMMIT=a1314bd0a47ecf2f41b85d5888a233d15e8a62a8

Author: ptomato

lib/zoneddatetime.ts

@@ -365,8 +365,8 @@ export class ZonedDateTime implements Temporal.ZonedDateTime {
     const instantStart = ES.BuiltinTimeZoneGetInstantFor(timeZone, dtStart, 'compatible');
     const endNs = ES.AddZonedDateTime(instantStart, timeZone, calendar, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0);
     const dayLengthNs = JSBI.subtract(endNs, JSBI.BigInt(GetSlot(instantStart, EPOCHNANOSECONDS)));
-    if (JSBI.equal(dayLengthNs, ZERO)) {
-      throw new RangeError('cannot round a ZonedDateTime in a calendar with zero-length days');
+    if (JSBI.lessThanOrEqual(dayLengthNs, ZERO)) {
+      throw new RangeError('cannot round a ZonedDateTime in a calendar with zero or negative length days');
     }
     ({ year, month, day, hour, minute, second, millisecond, microsecond, nanosecond } = ES.RoundISODateTime(
       year,

test/expected-failures-todo-migrated-code.txt

@@ -774,8 +774,6 @@ built-ins/Temporal/ZonedDateTime/prototype/round/roundingmode-halfCeil.js
 built-ins/Temporal/ZonedDateTime/prototype/round/roundingmode-halfEven.js
 built-ins/Temporal/ZonedDateTime/prototype/round/roundingmode-halfFloor.js
 built-ins/Temporal/ZonedDateTime/prototype/round/roundingmode-halfTrunc.js
-built-ins/Temporal/ZonedDateTime/prototype/round/smallest-unit-day-daylength-too-large.js
-built-ins/Temporal/ZonedDateTime/prototype/round/smallest-unit-day-daylength-zero-or-negative.js
 built-ins/Temporal/ZonedDateTime/prototype/round/timezone-getoffsetnanosecondsfor-out-of-range.js
 built-ins/Temporal/ZonedDateTime/prototype/second/timezone-getoffsetnanosecondsfor-out-of-range.js
 built-ins/Temporal/ZonedDateTime/prototype/since/argument-calendar-fields-undefined.js