Adds a "Discriminator" field to struct DILineInfo, which defaults to 0.
Fills out the "Discriminator" field in DILineInfo in DWARFDebugLine::LineTable::getFileLineInfoForAddress().
in order to have a slightly nicer interface in getFileLineInfoForAddress.
Patch by Simon Que!
Differential Revision: https://reviews.llvm.org/D27649
llvm-svn: 289683