[Bug go/81548] "make distclean" does not clean all of gotools/

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81548

--- Comment #5 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Well, distclean does  rm -rf $(TARGET_SUBDIR);  which takes care of a
lot (in the root generated Makefile).  Everything else is in gcc/, not
sure where that is deleted; gotools/ has the only .sum/.log outside of
those two dirs, it seems.