[8u] RFR: 8035437: Xerces Update: xml/serialize/DOMSerializerImpl

[Elliott Baron]

Hi,

I'm requesting a backport of 8035437 to 8u, as part of an update of 
Xerces to 2.12.0. Xerces should be updated for parity with Oracle JDK [1].

The JDK 9 patch requires some cosmetic changes to apply to 8u. These 
changes are outlined below categorized by file:
- com/sun/org/apache/xerces/internal/impl/XMLEntityManager
-- Copyright header differences
-- Import differences
- com/sun/org/apache/xml/internal/serialize/XMLSerializer
-- Copyright header differences
-- Import differences
-- Changed context due to previous backport of "8068842: Better JAXP 
data handling".
- com/sun/org/apache/xml/internal/serialize/BaseMarkupSerializer
-- Copyright header differences
-- Import differences
- com/sun/org/apache/xml/internal/serialize/DOMSerializerImpl
-- Context changes due to "8146961: Fix PermGen memory leaks caused by 
static final Exceptions" and "8011795: DOM Serializer prints stack 
traces to System.err"

Bug: https://bugs.openjdk.java.net/browse/JDK-8035437
8u Webrev: https://cr.openjdk.java.net/~ebaron/jdk8u/JDK-8035437/webrev.00/

Testing: x86_64 build, jdk_tier1, jdk_other (includes javax/xml) tests

Thanks,
Elliott

[1] https://bugs.openjdk.java.net/browse/JDK-8238164