The dwarf standard says that the only differences between a out-of-line

instance and a concrete inlined instance are the use of DW_TAG_subprogram
instead of DW_TAG_inlined_subroutine and the who owns the tree.

We were also omitting DW_AT_inline from the abstract roots. To fix this,
make sure we mark abstract instance roots with DW_AT_inline even when
we have only out-of-line instances referring to them with DW_AT_abstract_origin.

FileCheck is not a very good tool for tests like this, maybe we should add
a -verify mode to llvm-dwarfdump.

llvm-svn: 144441