Fixed a bug where DW_AT_start_scope would fall through to DW_AT_artificial in...

Fixed a bug where DW_AT_start_scope would fall through to DW_AT_artificial in SymbolFileDWARF::ParseVariableDIE(). This was caught by the clang warning that catches unannotated case fall throughs.

Author:    Greg Clayton <gclayton@apple.com>
Date:      Fri Mar 18 20:33:49 2016 +0000

This is a cherry-pick of r263824

llvm-svn: 270122