MdePkg DebugLib: Enable FILE NAME as DEBUG ASSERT for CLANG

MdePkg DebugLib: Enable FILE NAME as DEBUG ASSERT for CLANG

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1548
For clang compiler, This change will make the generated image not include the
absolute file path. If so, the generated debug image can be reproduced in the
different root directory. Also, it will reduce the size of debug image size.
To do so, use __FILE_NAME__ macro to replace __FILE__. __FILE_NAME__ is
Clang-specific extension that functions similar to __FILE__ but only renders
the last path component (the filename) instead of an invocation dependent full
path to that file, and __FILE_NAME__ is introduced since clang 9.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>