Build the complement interval dupli after the split intervals instead of

Build the complement interval dupli after the split intervals instead of
creating it before and subtracting split ranges.

This way, the SSA update code in LiveIntervalMap can properly create and use new
phi values in dupli. Now it is possible to create split regions where a value
escapes along two different CFG edges, creating phi values outside the split
region.

This is a work in progress and probably quite broken.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114492 91177308-0d34-0410-b5e6-96231b3b80d8