Revert "Invoke salvageDebugInfo from CodeGenPrepare's SinkCast()"

This reverts commit 317342 while investigating bot breakage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317345 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed