The systemtap testsuite subrpm is special in that it deliberately wants to request both 32- and 64-bit system libraries for testing.  Using the /usr/lib/libc.so seemed like the simplest way to accomplish part of this.  Since the -testsuite subrpm is of little to no interest to most users, I would not expect the filelists.xml download to hit hard.

(In reply to Frank Ch. Eigler from comment #1)
> The systemtap testsuite subrpm is special in that it deliberately wants to
> request both 32- and 64-bit system libraries for testing.  Using the
> /usr/lib/libc.so seemed like the simplest way to accomplish part of this. 
> Since the -testsuite subrpm is of little to no interest to most users, I
> would not expect the filelists.xml download to hit hard.

You need to close your component's bug, not this one.