[Bug go/83308] Missing platform definitions for SH in libgo

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83308

--- Comment #17 from Ian Lance Taylor <ian at airs dot com> ---
Actually we should just drop the libgo/go/exp directory.  I don't know why it's
still there.  It should have been dropped years ago.