JBR-1144 [JDK11] [macos] Held down key is not deleted when press backspace after accent menu popup (Mojave)

Handled backspace separately

(cherry picked from commit 81916a92af)

src/java.desktop/macosx/native/libawt_lwawt/awt/AWTView.m

@@ -299,7 +299,9 @@ static BOOL shouldUsePressAndHold() {
                    break;
             }
         }
-        return;
+        if ([event keyCode] != kVK_Delete) {
+            return;
+        }
     }
 
     NSString *eventCharacters = [event characters];