Provide the possiblity to switch between the direct and indirect RTTI symbols.

ncgrtti.pas, TRTTIWriter:
  + get_rtti_label, get_rtti_label_ord2str & get_rtti_label_str2ord: add new "indirect" parameter and pass that along to rtti_mangledname
hlcgobj.pas, thlcgobj:
  * g_incrrefcount, g_initialize, g_finalize, g_array_rtti_helper: for now pass along False to get_rtti_label()
ncgvmt.pas, TVMTWriter:
  * writevmt: for now pass along False to get_rtti_label()
ncgld.pas, tcgrttinode:
  * pass_generate_code: for now pass along False to the get_rtti_label*() methods

git-svn-id: http://svn.freepascal.org/svn/fpc/branches/svenbarth@28239 3ad0048d-3df7-0310-abae-a5850022a9f2