Reland "Adjust how we assign vtable indexes during class loading."

This reverts commit 07c2fec6b025d5cc104ab4f210c3941528f56fd6.

Bug: 211854716
Bug: 233545487
Bug: 181943478

Reason for revert: addressed comments

Change-Id: Id45c8e826b81f00190920a2b3270937614700f5f
17 files changed