Running ant with jdk7

[Michael Ernst]

> when I have ant run with jdk7 (jdk7/bin in my PATH), I'm getting
> this exception:
> 
> BUILD FAILED
> java.lang.IllegalArgumentException: invalid entry crc-32
>          at java.util.zip.ZipEntry.setCrc(ZipEntry.java:186)
>          at org.apache.tools.zip.ZipFile.populateFromCentralDirectory(ZipFile.java:300)
> ...

I get a similar "invalid entry crc-32", but only when I am compiling the
OpenJDK langtools project.  So, I use JDK 6 for that compilation.  I use
JDK 7 for everything else.  I have not had time to look into this further.

                    -Mike