Use absolute module path when possible if sent in svr4 packets

[fjricci]

Summary

If the remote uses svr4 packets to communicate library info,
the LoadUnload tests will fail, as lldb only used the basename
for modules, causing problems when two modules have the same basename.

Using absolute path as sent by the remote will ensure that lldb
locates the module from the correct directory when there are overlapping
basenames. When debugging a remote process, LoadModuleAtAddress will still
fall back to using basename and module_search_paths, so we don't
need to worry about using absolute paths in this case.

[ovyalov]

LGTM

lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp

for (LoadedModuleInfoList::LoadedModuleInfo & modInfo : module_list.m_list)
         valid &= modInfo.get_base (mod_base);
         valid &= modInfo.get_base_is_offset (mod_base_is_offset);
         if (!valid)
             continue;
 
         if (!modInfo.get_link_map (link_map))
             link_map = LLDB_INVALID_ADDRESS;
 
-        // hack (cleaner way to get file name only?) (win/unix compat?)
-        size_t marker = mod_name.rfind ('/');
-        if (marker == std::string::npos)
-            marker = 0;
-        else
-            marker += 1;
-
-        FileSpec file (mod_name.c_str()+marker, true);
+        FileSpec file (mod_name.c_str(), true);
         lldb::ModuleSP module_sp = LoadModuleAtAddress (file, link_map, mod_base,
                                                         mod_base_is_offset);
 
         if (module_sp.get())
             new_modules.Append (module_sp);
     }
 
     if (new_modules.GetSize() > 0)