Looks like a minor oversight that inadvertently introduced a dependency on sun.misc.Unsafe.

diff --git a/src/java.base/share/classes/java/lang/reflect/Proxy.java b/src/java.base/share/classes/java/lang/reflect/Proxy.java
--- a/src/java.base/share/classes/java/lang/reflect/Proxy.java
+++ b/src/java.base/share/classes/java/lang/reflect/Proxy.java
@@ -48,8 +48,8 @@
 
 import jdk.internal.loader.BootLoader;
 import jdk.internal.module.Modules;
+import jdk.internal.misc.Unsafe;
 import jdk.internal.misc.VM;
-import sun.misc.Unsafe;
 import sun.reflect.CallerSensitive;
 import sun.reflect.Reflection;
 import sun.reflect.misc.ReflectUtil;