Revert "[MachineOutliner] Never add the outliner in -O0"

This reverts commit 9c7c10e4073a0bc6a759ce5cd33afbac74930091.

It relies on r335872 since that introduces the machine outliner
flags test. I meant to commit D48683 in that commit, but got mixed
up and committed D48682 instead. So, I'm reverting this and
r335872, since D48682 hasn't made it through review yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335882 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed