Update references from "1.9" to "9"

This is a follow-up pass for JDK-8136494 which updated "@since 1.9" to "@since 9" to match java.specification.version.

The following files contain references to "1.9" which should be updated to "9":

jaxp:

src/java.xml/share/classes/com/sun/org/apache/xml/internal/serialize/BaseMarkupSerializer.java
src/java.xml/share/classes/com/sun/org/apache/xml/internal/serialize/XMLSerializer.java

jdk:

src/java.base/share/classes/jdk/internal/vm/annotation/ReservedStackAccess.java
src/java.logging/share/classes/java/util/logging/SimpleFormatter.java
src/java.logging/share/classes/java/util/logging/XMLFormatter.java