One HotSpot virtual machine internal class to indicate an area of dead (unreachable) memory has been renamed to conform to the Java class naming standard to avoid confusing external applications parsing virtual machine class histograms provided by `jmap -histo`.

There are applications that parse the output of `jmap -histo` which fail when encountering the class `jdk.vm.internal.FillerArray`. In particular, the issue is that this type of filler object represents a flexibly sized range of unreachable memory but is named as if it were a fixed size non-array object. Then, for example, calculating the instance size of these objects from the `jmap -histo` output can result in non-integral instance sizes, confusing applications.

This problem has been fixed by changing the name of this class to the array-like name `[Ljdk/internal/vm/FillerElement;`.