Allow place KotlinSignature annotation to methods

runtime/src/jet/runtime/typeinfo/KotlinSignature.java

@@ -23,7 +23,7 @@ import java.lang.annotation.Target;
  * @author Evgeny Gerashchenko
  * @since 5/23/12
  */
-@Target({ElementType.METHOD, ElementType.TYPE, ElementType.CONSTRUCTOR})
+@Target({ElementType.METHOD, ElementType.TYPE, ElementType.CONSTRUCTOR, ElementType.FIELD})
 public @interface KotlinSignature {
     String value();
 }