Fix run-test after introduction of VDEX

Run-test 119-noimage-patchoat used to fail due to a codepath in
OatFile which allows to create an instance of the class from an
existing ElfFile instance. This patch updates the codepath to require
an existing VdexFile as well.

Test: art/test/run-test 119
Bug: 30937355
Change-Id: I8fd0e47f07921aaee999f73711766ada9c35d214
3 files changed