DebugInfo: Fix missing inlined_subroutines caused by r208748.

The check in DwarfDebug::constructScopeDIE was meant to consider inlined
subroutines as any non-top-level scope that was a subprogram. Instead of
checking "not top level scope" it was checking if the /subprogram's/
scope was non-top-level.

Fix this and beef up a test case to demonstrate some of the missing
inlined_subroutines are no longer missing.

In the course of fixing this I also found that r208748 (with this fix)
found one /extra/ inlined_subroutine in concrete_out_of_line.ll due to
two inlined_subroutines having the same inlinedAt location. The previous
implementation was collapsing these into a single inlined subroutine.

I'm not sure what the original code was that created this .ll file so
I'm not sure if this actually happens in practice today. Since we
deliberately include column information to disambiguate two calls on the
same line, that may've addressed this bug in the frontend, but it's good
to know that workaround isn't necessary for this particular case
anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209165 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Don't include DW_AT_inline on each abstract definition multiple times.

When I refactored this in r208636 I accidentally caused this to be added
multiple times to each abstract subprogram (not accounting for the
deduplicating effect of the InlinedSubprogramDIEs set).

This got better in r208798 when the abstract definitions got the
attribute added to them at construction time, but still had the
redundant copies introduced in r208636.

This commit removes those excess DW_AT_inlines and relies solely on the
insertion in r208798.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209166 91177308-0d34-0410-b5e6-96231b3b80d8