Added IllegalThreadStateException, which is used by java.lang.Process

classpath/java/lang/IllegalThreadStateException.java

@@ -0,0 +1,20 @@
+package java.lang;
+
+public class IllegalThreadStateException extends IllegalArgumentException {
+  public IllegalThreadStateException(String message, Throwable cause) {
+    super(message, cause);
+  }
+
+  public IllegalThreadStateException(String message) {
+    this(message, null);
+  }
+
+  public IllegalThreadStateException(Throwable cause) {
+    this(null, cause);
+  }
+
+  public IllegalThreadStateException() {
+    this(null, null);
+  }
+
+}