ART: Dump referenced type in IRT overflows

When the runtime dumps a reference table, e.g., when aborting for
an overflow, dump the type of stored referents for reference types
to aid in debugging leaks.

Bug: 31600693
Test: m test-art-host-gtest-reference_table_test
Change-Id: Ia892dc84ca8827dd93a8b75d6f571c392f94859c
(cherry picked from commit 280f32b0)