- remove ashr which never worked.
- fix lshr and shl and add tests.
- remove dead function "intersect1Wrapped".
- add a new sub method to subtract ranges, with test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110861 91177308-0d34-0410-b5e6-96231b3b80d8