[8u] RFR: 8041523: Xerces Update: Serializer improvements from Xalan

[Ekaterina Vergizova]

Hello,
I would like to backport JDK-8041523 to 8u. It should be included to monojdk8u as a critical fix.

This backport fixes jck8 api/xinclude test failures that occur after JDK-8037259 backport to 8u.
Аffected tests:
api/xinclude/Nist/Nist-include-38.html#Nist-include-38
api/xinclude/Nist/Nist-include-37.html#Nist-include-37
api/xinclude/Harold/harold-64.html#harold-64

JBS: https://bugs.openjdk.java.net/browse/JDK-8041523
Original patch: http://hg.openjdk.java.net/jdk9/jdk9/jaxp/rev/894ae6562453
Webrev for 8u: https://cr.openjdk.java.net/~apetushkov/8041523/webrev.00/

Original patch from jdk9 applies almost cleanly except for some copyright differences and imports reshuffling.

Tested with jdk_tier1, jdk_other (that includes javax/xml) and jck8 api/xinclude.

Thanks,
Ekaterina