Patch from dexonsmith. The call to toInt() was calling compareTo() which
in some cases would call back to toInt(), creating an infinite loop.
Fixed by simplifying the logic in compareTo() to avoid the co-recursion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236326 91177308-0d34-0410-b5e6-96231b3b80d8