8176188: jdk/internal/misc/JavaLangAccess/NewUnsafeString.java failing since 9-b93

Reviewed-by: psandoz, sherman

src/java.base/share/classes/java/lang/System.java

@@ -2109,9 +2109,6 @@ public final class System {
             public void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook) {
                 Shutdown.add(slot, registerShutdownInProgress, hook);
             }
-            public String newStringUnsafe(char[] chars) {
-                return new String(chars, true);
-            }
             public Thread newThreadWithAcc(Runnable target, AccessControlContext acc) {
                 return new Thread(target, acc);
             }