To avoid the conflict with the default GCC flag name, BUILD_ prefix is added. Cc: Giri P Mudusuru <giri.p.mudusuru@intel.com> Cc: Yonghong Zhu <yonghong.zhu@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Liming Gao <liming.gao@intel.com> Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com> Reviewed-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>