Temporal.PlainTime#since should handle ceil/floor properly

https://bugs.webkit.org/show_bug.cgi?id=241623

Reviewed by Yusuke Suzuki.

This patch adds a spec step that our implementation was missing:

    DifferenceTemporalPlainTime ( operation, temporalTime, other, options )
        ...
        9. If operation is ~since~, then
            a. Set roundingMode to ! NegateTemporalRoundingMode(roundingMode).

* JSTests/test262/expectations.yaml:
Mark four test cases as passing.

* Source/JavaScriptCore/runtime/TemporalPlainTime.cpp:
(JSC::TemporalPlainTime::since const):

Canonical link: https://commits.webkit.org/251555@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@295550 268f45cc-cd09-0410-ab3c-d52691b4dbfc

JSTests/test262/expectations.yaml

@@ -1080,12 +1080,6 @@ test/built-ins/Temporal/PlainTime/prototype/equals/argument-zoneddatetime-timezo
 test/built-ins/Temporal/PlainTime/prototype/since/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js:
   default: "TypeError: undefined is not a constructor (evaluating 'new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, timeZone)')"
   strict mode: "TypeError: undefined is not a constructor (evaluating 'new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, timeZone)')"
-test/built-ins/Temporal/PlainTime/prototype/since/roundingmode-ceil.js:
-  default: 'Test262Error: hours hours result Expected SameValue(«4», «5») to be true'
-  strict mode: 'Test262Error: hours hours result Expected SameValue(«4», «5») to be true'
-test/built-ins/Temporal/PlainTime/prototype/since/roundingmode-floor.js:
-  default: 'Test262Error: hours hours result Expected SameValue(«5», «4») to be true'
-  strict mode: 'Test262Error: hours hours result Expected SameValue(«5», «4») to be true'
 test/built-ins/Temporal/PlainTime/prototype/until/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js:
   default: "TypeError: undefined is not a constructor (evaluating 'new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, timeZone)')"
   strict mode: "TypeError: undefined is not a constructor (evaluating 'new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, timeZone)')"

Source/JavaScriptCore/runtime/TemporalPlainTime.cpp

@@ -647,6 +647,12 @@ ISO8601::Duration TemporalPlainTime::since(JSGlobalObject* globalObject, Tempora
     auto [smallestUnit, largestUnit, roundingMode, increment] = extractDifferenceOptions(globalObject, optionsValue);
     RETURN_IF_EXCEPTION(scope, { });
 
+    // https://tc39.es/proposal-temporal/#sec-temporal-negatetemporalroundingmode
+    if (roundingMode == RoundingMode::Ceil)
+        roundingMode = RoundingMode::Floor;
+    else if (roundingMode == RoundingMode::Floor)
+        roundingMode = RoundingMode::Ceil;
+
     auto result = differenceTime(other->plainTime(), plainTime());
     result = -result;
     result.setYears(0);