Oops. Bad typo. Without the check of N1.hasOneUse() bad things can happen.

Suppose the TokenFactor can reach the Op:

       [Load chain]
           ^
           |
         [Load]
         ^    ^
         |    |
        /      \-
       /         |
      /          [Op]
     /          ^ ^
     |        ..  |
     |       /    |
   [TokenFactor]  |
       ^          |
       |          |
        \        /
         \      /
         [Store]

If we move the Load below the TokenFactor, we would have created a cycle in
the DAG.

llvm-svn: 30040