Drop the five Temporal members the proposal removed

[lahma]

#2996 dropped the Temporal.Now methods the proposal removed. Five more members from the same June 2024 removals were still exposed; this takes them out.

• Temporal.PlainDateTime.prototype.withPlainDate
• Temporal.ZonedDateTime.prototype.epochSeconds
• Temporal.ZonedDateTime.prototype.epochMicroseconds
• Temporal.ZonedDateTime.prototype.toPlainYearMonth
• Temporal.ZonedDateTime.prototype.toPlainMonthDay

None of them appears in the live proposal. Properties of the Temporal.PlainDateTime Prototype Object lists 22 accessors and 17 methods, withPlainTime among them and no withPlainDate. Properties of the Temporal.ZonedDateTime Prototype Object lists 28 accessors and 21 methods, with epochMilliseconds and epochNanoseconds the only two epoch accessors and toPlainDate / toPlainTime / toPlainDateTime the only three toPlain* methods. With the five gone, Object.getOwnPropertyNames reports 39 names on PlainDateTime.prototype and 49 on ZonedDateTime.prototype, matching those lists name for name.

This is breaking for anyone calling them, which is why it lands early in the 4.16 cycle rather than late. The replacements are what the proposal points at: pdt.withPlainDate(d) becomes d.toPlainDateTime(pdt.toPlainTime()), zdt.epochSeconds becomes zdt.epochMilliseconds / 1000 (floored) or zdt.epochNanoseconds / 1_000_000_000n, zdt.epochMicroseconds becomes zdt.epochNanoseconds / 1000n, and zdt.toPlainYearMonth() / zdt.toPlainMonthDay() become zdt.toPlainDate().toPlainYearMonth() / zdt.toPlainDate().toPlainMonthDay(), both of which PlainDate.prototype keeps.

Nothing is orphaned. FloorDivide sits between the two removed accessors and still serves epochMilliseconds, so the deletion is not one contiguous block. ToTemporalDate, and the IsoDate overloads of PlainYearMonthConstructor.Construct and PlainMonthDayConstructor.Construct, all keep other callers. Deleting the attributed method is the whole edit — Jint.SourceGenerators/ObjectGenerator emits the property table and computes the BuiltinShape.Builder capacity from the attributes, so the regenerated shapes went to 39 and 49 on their own with no hand-written count to decrement.

test262

No exclusion was needed. At the pinned SHA (3655e7464de3d52643ecddd4b5f9f4f3e7f62398) all five test directories are already gone upstream — built-ins/Temporal/PlainDateTime/prototype/withPlainDate, and built-ins/Temporal/ZonedDateTime/prototype/{epochSeconds,epochMicroseconds,toPlainYearMonth,toPlainMonthDay}. Nothing else in built-ins/ or intl402/ reaches these members; the remaining toPlainYearMonth / toPlainMonthDay hits are all on PlainDate.prototype, which keeps them. The only place the suite asserts their absence is staging/Temporal/removed-methods.js, and Jint's harness generates annexB, built-ins, intl402 and language only — so, exactly as in #2996, nothing in the suite was holding the line. TemporalRemovedMembersTests pins both full property lists instead, and cites that staging file.

Pre-fix failure

The test was written first and run against the unfixed engine. 7 of its 8 cases failed; the eighth is the survivors control, which passes either way:

Failed Jint.Tests.Runtime.TemporalRemovedMembersTests.DoesNotExposeTheRemovedMembers(type: "Temporal.ZonedDateTime", removed: "epochSeconds")
  Expected engine.Evaluate($"'{removed}' in {type}.prototype").AsBoolean() to be False, but found True.

Failed Jint.Tests.Runtime.TemporalRemovedMembersTests.PlainDateTimePrototypeExposesExactlyTheMembersTheProposalDefines
  Expected string to be the same string, but they differ at index 342:
  "…,withPlainDate,withPlainTime,year,yearOfWeek"   (actual)
  "…,withPlainTime,year,yearOfWeek"                 (expected)

Failed Jint.Tests.Runtime.TemporalRemovedMembersTests.ZonedDateTimePrototypeExposesExactlyTheMembersTheProposalDefines
  Expected string to be the same string, but they differ at index 92:
  "…ar,epochMicroseconds,epochMilliseconds,epochNanose…"   (actual)
  "…ar,epochMilliseconds,epochNanoseconds,equals,era,e…"   (expected)

Failed!  - Failed: 7, Passed: 1, Total: 8

Verification

Release, freshly built, all green:

Suite	Result
dotnet build -c Release	0 errors, 0 compiler warnings
Jint.Tests net10.0	5668 passed, 4 skipped
Jint.Tests net472	5584 passed, 4 skipped
Jint.Tests.PublicInterface net10.0	1486 passed, 9 skipped
Jint.Tests.PublicInterface net472	1485 passed, 9 skipped
Jint.Tests.Test262	99779 passed, 122 skipped, 0 failed

Closes #3010

🤖 Generated with Claude Code