Completely change the way that joining with physregs is implemented.  This
paves the way for future changes, increases coallescing opportunities (in
theory, not witnessed in practice), and eliminates the really expensive
LiveIntervals::overlapsAliases method.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29890 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed