Revert r135217, which wasn't the correct fix for PR10358. With this

patch, we actually move the state-machine for the value set backwards
one step. This can pretty easily lead to infinite loops where we
continually try to propagate a bit, succeed for one iteration, but then
back up because we find an uninitialized use.

A reduced test case from PR10379 is included.

llvm-svn: 135359