Revert "[SelectionDAG] Selection of DBG_VALUE using a PHI node result (pt 2)"

This reverts SVN r331337, see PR37321 for details on the regression
it introduced.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331441 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed