This module is particularly useful to those who write XSUB, thereby reducing a bother.
The author of the module, Goro Fuji, simply puts the features in perl-users.jp/articles/advent-calenda... (unfortunately written in Japanese) as follows:
Carrying compiler warnings into effect.
Automatically generating the specific version of ppport.h.
Needless to say, there are other features as to compiling options.