ART: Fix assumption in class profile collection

The dex cache may contain erroneous classes. Filter, instead of
DCHECK.

Bug: 27500691

(cherry picked from commit 4309f6129795ade42591b872e44a33cec95f4e79)

Change-Id: Ic99bca3a7e54a5e7893c801ec5ac92cbf690cd67
1 file changed