This DAG combine BRCOND transformation can look pass truncate of the operand:

This DAG combine BRCOND transformation can look pass truncate of the operand:
    //   %a = ...
    //   %b = and i32 %a, 2
    //   %c = srl i32 %b, 1
    //   brcond i32 %c ...
    //
    // into
    //
    //   %a = ...
    //   %b = and i32 %a, 2
    //   %c = setcc eq %b, 0
    //   brcond %c ...

Make sure it restores local variable N1, which corresponds to the condition operand if it fails to match.

This apparently breaks TCE but since that backend isn't in the tree I don't have a test for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115571 91177308-0d34-0410-b5e6-96231b3b80d8