[Test] Reenable most arm64e concurrency tests.

rdar://72357371

Author: nate-chandler

test/Concurrency/Runtime/actor_counters.swift

@@ -6,6 +6,8 @@
 
 // Remove with rdar://problem/72439642
 // UNSUPPORTED: asan
+// Remove with rdar://problem/72357371
+// UNSUPPORTED: CPU=arm64e
 
 #if canImport(Darwin)
 import Darwin

test/Concurrency/Runtime/mainactor.swift

@@ -5,6 +5,8 @@
 
 // REQUIRES: OS=macosx || OS=ios
 // FIXME: should not require Darwin to run this test once we have async main!
+// Remove with rdar://problem/72357371
+// UNSUPPORTED: CPU=arm64e
 
 // for exit(:Int)
 #if canImport(Darwin)

test/Concurrency/Runtime/objc_async.swift

@@ -7,6 +7,9 @@
 // REQUIRES: concurrency
 // REQUIRES: objc_interop
 
+// Remove with rdar://problem/72357371
+// UNSUPPORTED: CPU=arm64e
+
 
 @main struct Main {
   static func main() async {

test/lit.cfg

@@ -355,10 +355,6 @@ run_ptrauth = 'ptrauth' if run_cpu == 'arm64e' else 'noptrauth'
 run_endian = 'little' if run_cpu != 's390x' else 'big'
 run_objc_interop = 'nonobjc'      # overwritten later
 
-if run_cpu == 'arm64e':
-    lit_config.warning('Skipping concurrency tests on arm64e for now.  Remove with rdar://problem/72357371 .')
-    config.available_features.discard('concurrency')
-
 sdk_overlay_link_path = ""
 sdk_overlay_linker_opt = ""
 sdk_overlay_dir_opt = ""