quick sketch of java/io/*

classpath/java/io/FileInputStream.java

@@ -0,0 +1,15 @@
+package java.io;
+
+public class FileInputStream extends InputStream {
+  private final FileDescriptor fd;
+
+  public FileInputStream(FileDescriptor fd) {
+    this.fd = fd;
+  }
+
+  public native int read() throws IOException;
+
+  public native int read(byte[] b, int offset, int length) throws IOException;
+
+  public native void close() throws IOException;
+}