RFR: 8073872: Schemagen fails with StackOverflowError if element references containing class

[Aleksej Efimov]

Hi,

Please, help to review the fix for JDK-8073872 [1]. In JDK9 this bug was 
fixed as part of sync with upstream JAXWS project [2]. The changes that 
fixed stack overflow issue are located in XmlSchemaGenerator class [3].
JDK9 change that needs review is the addition of regression test for 
this issue:
http://cr.openjdk.java.net/~aefimov/8073872/9/00/

I will be requesting JDK8 approval for partially backporting the fix for 
this bug to 8u-dev. Can I also ask to review the JDK8 changes:
http://cr.openjdk.java.net/~aefimov/8073872/8/00/

Both JDK8/9 changes were tested with JCK/JTREG tests and no failures 
were observed. New test passes with the fix and successfully reproduces 
reported stack overflow on JDKs without the fix.

Best Regards,
Aleksej

[1] https://bugs.openjdk.java.net/browse/JDK-8073872
[2] https://bugs.openjdk.java.net/browse/JDK-8150174
[3] http://hg.openjdk.java.net/jdk9/jdk9/jaxws/rev/ebff1bd3627a#l3.2