[CodeGen] Unify the syntax of MBB liveins in MIR and -debug output

Instead of:

Live Ins: %r0 %r1

print:

liveins: %r0, %r1

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324694 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed