Revert "Enable EliminateAvailableExternally pass for -O1"

This reverts commit r330961 because it breaks a handful of clang tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330964 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed