Move enabling the local stack allocation pass into the target where it belongs.

Move enabling the local stack allocation pass into the target where it belongs.
For now it's still a command line option, but the interface to the generic
code doesn't need to know that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111942 91177308-0d34-0410-b5e6-96231b3b80d8