Executables append omnitrace library directory to LD_LIBRARY_PATH (#356)

- omnitrace-run, omnitrace-sample, and omnitrace-causal now automatically append the LD_LIBRARY_PATH with the directory containing the omnitrace libraries
  - this helps ensure that binary rewritten exes can resolve omnitrace-rt library location

source/lib/core/argparse.cpp

@@ -248,6 +248,15 @@ add_ld_preload(parser_data& _data)
     return _data;
 }
 
+parser_data&
+add_ld_library_path(parser_data& _data)
+{
+    auto _libdir = filepath::dirname(_data.dl_libpath);
+    if(filepath::exists(_libdir))
+        update_env(_data, "LD_LIBRARY_PATH", _libdir, UPD_APPEND);
+    return _data;
+}
+
 parser_data&
 add_core_arguments(parser_t& _parser, parser_data& _data)
 {