Current GenFds Tool class GuidSection() is parsing the tools_def.txt for every GUID'ed section that has a GUID defined tool, it cause a bad performance. so this patch cache the defined Guid tool to improve the performance. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>