LiveRangeCalc: Rewrite subrange calculation

This changes subrange calculation to calculate subranges sequentially
instead of in parallel. The code is easier to understand that way and
addresses the code review issues raised about LiveOutData being
hard to understand/needing more comments by removing them :)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224313 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: 80-column

clang-format a function with an overly long string constant.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224314 91177308-0d34-0410-b5e6-96231b3b80d8