[8u] RFR Backport 8046724: XML Signature ECKeyValue elements cannot be marshalled or unmarshalled

[Elliott Baron]

Hi,

I'd like to request a review to backport 8046724 to 8u. This change is a 
dependency that will help us do a cleaner backport of "8177334: Update 
xmldsig implementation to Apache Santuario 2.1.1".

Original fix:
https://bugs.openjdk.java.net/browse/JDK-8046724
https://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/eed55a6ebaa3

The JDK 9 changeset did not apply cleanly. Here are the modifications I 
had to make to backport this to 8u:

DOMKeyValue.java:
- Also removes commented out java.io.IOException import statement, which 
would have been removed by "8046949: Generify the javax.xml.crypto API", 
which I didn't backport since it changes API. This changeset effectively 
uncomments this statement, since IOException is used once again.
- Edited strings in code deleted by this changeset from 
"sun.security.util.ECParameters" to "sun.security.ec.ECParameters". This 
is because "8035166: Remove dependency on EC classes from pkcs11 
provider" is not in 8u.

GenerationTests.java:
- Copyright header already updated to newer date by "8206911: 
javax/xml/crypto/dsig/GenerationTests.java fails in 8u-dev".
- jtreg tag is missing "8046949: Generify the javax.xml.crypto API". The 
tag includes two bugs newer than this one: "8074784: Additional tests 
for XML DSig API", and "8210736: 
jdk/javax/xml/crypto/dsig/GenerationTests.java slow on linux".

8u webrev:
https://cr.openjdk.java.net/~ebaron/jdk8u/JDK-8046724/webrev.00/

Testing: x86_64 build, jdk_tier1, jdk_security tests

Thanks,
Elliott