Replace r102368 with code that's less fragile. This creates DBG_VALUE instructions...

Replace r102368 with code that's less fragile. This creates DBG_VALUE instructions for function arguments early and insert them after instruction selection is done.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102554 91177308-0d34-0410-b5e6-96231b3b80d8