Revert "Add new symbols to the ABI tests"

This reverts commit de0288a.

Author: DougGregor

test/abi/macOS/arm64/concurrency.swift

@@ -298,10 +298,6 @@ Added: _$sScg4next9isolationxSgScA_pSgYi_tYaKFTu
 Added: _$sScg22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaF
 Added: _$sScg22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaFTu
 
-// next() default implementation in terms of next(isolation:)
-Added: _$sScIsE4next7ElementQzSgyYa7FailureQzYKF
-Added: _$sScIsE4next7ElementQzSgyYa7FailureQzYKFTu
-
 // === SerialExecutor.checkIsolated()
 Added: _swift_task_checkIsolated
 Added: _swift_task_checkIsolated_hook
@@ -318,4 +314,4 @@ Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__y
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlFTu
 // Swift.TaskLocal.withValue<A>(_: A, operation: () async throws -> A1, isolation: isolated Swift.Actor?, file: Swift.String, line: Swift.UInt) async throws -> A1
 Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlF
-Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlFTu
+Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlFTu

test/abi/macOS/x86_64/concurrency.swift

@@ -284,7 +284,6 @@ Added: _$ss26withTaskExecutorPreference_9isolation9operationxSch_pSg_ScA_pSgYixy
 // async function pointer to Swift.withTaskExecutorPreference<A, B where B: Swift.Error>(_: Swift.TaskExecutor?, isolation: isolated Swift.Actor?, operation: () async throws(B) -> A) async throws(B) -> A
 Added: _$ss26withTaskExecutorPreference_9isolation9operationxSch_pSg_ScA_pSgYixyYaq_YKXEtYaq_YKs5ErrorR_r0_lFTu
 
-// === Add #isolation to next() and waitForAll() in task groups
 // Swift.TaskGroup.awaitAllRemainingTasks(isolation: isolated Swift.Actor?) async -> ()
 Added: _$sScG22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaF
 Added: _$sScG22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaFTu
@@ -298,10 +297,6 @@ Added: _$sScg4next9isolationxSgScA_pSgYi_tYaKFTu
 Added: _$sScg22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaF
 Added: _$sScg22awaitAllRemainingTasks9isolationyScA_pSgYi_tYaFTu
 
-// next() default implementation in terms of next(isolation:)
-Added: _$sScIsE4next7ElementQzSgyYa7FailureQzYKF
-Added: _$sScIsE4next7ElementQzSgyYa7FailureQzYKFTu
-
 // === SerialExecutor.checkIsolated()
 Added: _swift_task_checkIsolated
 Added: _swift_task_checkIsolated_hook
@@ -318,4 +313,4 @@ Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__y
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlFTu
 // Swift.TaskLocal.withValue<A>(_: A, operation: () async throws -> A1, isolation: isolated Swift.Actor?, file: Swift.String, line: Swift.UInt) async throws -> A1
 Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlF
-Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlFTu
+Added: _$ss9TaskLocalC9withValue_9operation9isolation4file4lineqd__x_qd__yYaKXEScA_pSgYiSSSutYaKlFTu