minification R: build-system

[zimoun]

Hi,

Recently, the switch from uglify-js to uglifyjs raises a question if
this minification should be part of the r-build-system; as suggested
by Ricardo:

<http://logs.guix.gnu.org/guix-hpc/2021-09-22.log#160424>

What people think to this move?  Because, currently the replacement of
the minifier means grep and replace all by hand, i.e., prone-error.
It should be nice to add a step for the R packages.  WDYT?


All the best,
simon