[JAVA] Respect parsedir and objdocdir

[Andrew Haley]

Ranjit Mathew writes:
 > Hi Kelly,
 > 
 >     IMHO, you should also CC the java-patches mailing
 > list on Java front-end patches.
 > 
 > Another nit: IMHO, you should generate diffs against
 > the "java" folder (i.e. $GCC_SOURCE/gcc/java)
 > to make it easier to apply such patches, especially
 > via automation tools.
 > 
 > Ranjit.
 > 
 > PS: I didn't mean to single out just your patch - there
 > have been other Java front-end patches on gcc-patches
 > recently that weren't also posted to java-patches.

Several of them mine, I fear.  Alright, I'll try to be better.

Andrew.