DebugInfo: don't use location lists when the location covers the whole function anyway

Fix up three tests - one that was relying on abbreviation number,
another relying on a location list in this case (& testing raw asm,
changed that to use dwarfdump on the debug_info now that that's where
the location is), and another which was added in r184368 - exposing a
bug in that fix that is exposed when we emit the location inline rather
than through a location list. Fix that bug while I'm here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184387 91177308-0d34-0410-b5e6-96231b3b80d8