Add the knob NEW_GET_SOURCE_LINES to Struct.cpp.  The API for getSourceLines() has changed between Dyninst 9.2 and the current line_info branch (pre-9.3).  So, we support both with a #if.
Add the knob NEW_GET_SOURCE_LINES to Struct.cpp.  The API for
getSourceLines() has changed between Dyninst 9.2 and the current
line_info branch (pre-9.3).  So, we support both with a #if.

Also, change the knobs to use the libdwarf line map info.  We will
probably use this in the initial merge to master until all the bugs
are worked out.

HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit