Fixed a problem where the DWARF for inline functions was mis-parsed.

Inline functions in DWARF have AT_abstract_origin set, but we only handled that
if the functions were C++ methods.  Inline functions -- C or C++ -- have this
also, and as a result they got one FunctionDecl for each inlined instance.  When
going to construct the locals, this meant that the arguments (which did properly
have their abstract origins handled) would get associated with the master
FunctionDecl, and the inlined FunctionDecls would all appear to have no locals.

This manifested as not being able to look up local variables when stopped in an
inline fuunction.  We should have had a test for this, but somewhere along the
line the relevant test case lost its .py file (or it never had one).

This patch fixes this problem and restores the .py file.

<rdar://problem/24712434>

Author:    Sean Callanan <scallanan@apple.com>
Date:      Tue Feb 23 00:51:52 2016 +0000

This is a cherry-pick of r261598

llvm-svn: 270117