nashorn should only use jdk8 apis in the compact1 profile

For java applications targeted to run on the compact1 profile of jdk8 to use nashorn, nashorn must not itself use any JDK8 APIs that are not in compact1. A scan of nashorn.jar today using jdeps reveals the use of some APIs from the compact3 profile. This usage should be removed.

jdeps -profile /d/jdk8/jre/lib/ext/nashorn.jar |grep compact3
d:\jdk8\jre\lib\ext\nashorn.jar -> d:\jdk8\jre\lib\rt.jar (compact3, JDK internal API)
      -> java.lang.management compact3

jdeps -profile -verbose:class /d/jdk8/jre/lib/ext/nashorn.jar |grep management
      -> java.lang.management.ManagementFactory compact3
      -> java.lang.management.MemoryPoolMXBean compact3
      -> java.lang.management.MemoryUsage compact3

a quick scan of the nashorn sources reveals the usage is in
src/jdk/nashorn/internal/ir/debug/ObjectSizeCalculator.java