SplitKit requires that all defs are in place before calling useIntv().

SplitKit requires that all defs are in place before calling useIntv().

The value mapping gets confused about which original values have multiple new
definitions so they may need phi insertions.

This could probably be simplified by letting enterIntvBefore() take a live range
to be added following the instruction. As long as the range stays inside the
same basic block, value mapping shouldn't be a problem.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123926 91177308-0d34-0410-b5e6-96231b3b80d8