ltcl: check for tcl8.6 and define USE_INTERP_RESULT
ltcl: check for tcl8.6 and define USE_INTERP_RESULT

andrew-d/luabuild,yuhangwang/luabuild,stevedonovan/luabuild,andrew-d/luabuild,stevedonovan/luabuild,yuhangwang/luabuild,yuhangwang/luabuild,andrew-d/luabuild,yuhangwang/luabuild,stevedonovan/luabuild,andrew-d/luabuild,andrew-d/luabuild,stevedonovan/luabuild,yuhangwang/luabuild,stevedonovan/luabuild