Another bug in multifile processing.  With these two classes:

Pipe.java:
  package java.nio.channels;
  import java.nio.channels.spi.AbstractSelectableChannel;
  public abstract class Pipe { }

SelectableChannel.java:
  package java.nio.channels;
  import java.nio.channels.spi.AbstractInterruptibleChannel;
  public abstract class SelectableChannel extends AbstractInterruptibleChannel
  { }

jc1 compiles Pipe.java on its own, but fails to compile the two files together
with an

Pipe.java:3: internal compiler error: tree check: expected class 'expression',
have 'constant' (integer_cst) in make_class_data, at java/class.c:1572

for SelectableChannel.  Looks like another bug related to imports, because size
is an error_mark, and because inverting the order of the files works around the bug.

This is with my patch for 21436.