Restore Instant and Clock as type aliases to kotlin.time

Author: dkhalanskyjb

core/common/src/DeprecatedClock.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2019-2025 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime
+
+@Deprecated(
+    "This type is deprecated in favor of `kotlin.time.Clock`.",
+    level = DeprecationLevel.WARNING,
+    replaceWith = ReplaceWith("kotlin.time.Clock", "kotlin.time.Clock"))
+public typealias Clock = kotlin.time.Clock

core/common/src/DeprecatedInstant.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2019-2025 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime
+
+@Deprecated(
+    "This type is deprecated in favor of `kotlin.time.Instant`.",
+    level = DeprecationLevel.WARNING,
+    replaceWith = ReplaceWith("kotlin.time.Instant", "kotlin.time.Instant"))
+public typealias Instant = kotlin.time.Instant