You don't actually save anything on disk on most file systems
(essentially everything except reiserfs on current Linux)
because all files are rounded to block size (normally 4K)
Same in page cache.
And in tar files bzip2/gzip is very good at compacting them.
Many kernel maintainers automatically remove trailing white space on any new
lines these days. So as the kernel keeps changing it should eventually all
disappear; except on essentially dead code.
-Andi
-