Dump runtime_internal_objects in the graph

The old hprof does a similar thing here and creates a synthetic
runtimeInternalObjects field for references dumped by `VisitRoot`.

This commit dumps them in a special way in the graph instead.

Bug: 424237741
Flag: EXEMPT bugfix
Change-Id: Iee02a33c373d22843d0177d599d9cafbb3610c9c
1 file changed