Add further nio stubs

 - Add {FileAlreadyExists,NoSuchFile,NotADirectory}Exception.
 - Add OpenOption interface and StandardOpenOption enum.

classlib/src/main/java/org/teavm/classlib/java/nio/file/TFileAlreadyExistsException.java

@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2023 Jonathan Coates.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio.file;
+
+public class TFileAlreadyExistsException extends TFileSystemException {
+    private static final long serialVersionUID = -8210257702245084985L;
+
+    public TFileAlreadyExistsException(String file) {
+        super(file);
+    }
+
+    public TFileAlreadyExistsException(String file, String other, String reason) {
+        super(file, other, reason);
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TNoSuchFileException.java

@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2023 Jonathan Coates.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio.file;
+
+public class TNoSuchFileException extends TFileSystemException {
+    private static final long serialVersionUID = -2724052005589959528L;
+
+    public TNoSuchFileException(String file) {
+        super(file);
+    }
+
+    public TNoSuchFileException(String file, String other, String reason) {
+        super(file, other, reason);
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TNotDirectoryException.java

@@ -0,0 +1,24 @@
+/*
+ *  Copyright 2023 Jonathan Coates.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio.file;
+
+public class TNotDirectoryException extends TFileSystemException {
+    private static final long serialVersionUID = 2268196534868848834L;
+
+    public TNotDirectoryException(String file) {
+        super(file);
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TOpenOption.java

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2023 Jonathan Coates.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio.file;
+
+public interface TOpenOption {
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TStandardOpenOption.java

@@ -0,0 +1,29 @@
+/*
+ *  Copyright 2023 Jonathan Coates.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio.file;
+
+public enum TStandardOpenOption implements TOpenOption {
+    READ,
+    WRITE,
+    APPEND,
+    TRUNCATE_EXISTING,
+    CREATE,
+    CREATE_NEW,
+    DELETE_ON_CLOSE,
+    SPARSE,
+    SYNC,
+    DSYNC,
+}