Currently, thirteen files which provide a target_ops explicitly initialize
members they don't support to NULL. I plan to delete a number of these
methods, and rather than making sure I got all the necessary target files
each time I just wanted to delete the unnecessary lines up-front. All of
these are called-once functions initializing a statically or globally
declared object; C will guarantee zero-initialization for us. And several
of the functions explicitly called memset anyway.
Besides, this way grepping for .to_require_attach\ = will only find targets
which define it to something useful.
I'll commit this tomorrow unless someone sees a problem with it.
Note1: remote-st.c hasn't been compilable in a while; m68*-tandem-* is
probably a good candidate for the hitlist. From a glance it looks like it
has been broken since the HP merge added the NULL assignments I'm removing,
which is about three years now I think.
Note2: The DONT_USE member of struct target_ops can go now.
The fact that 13 files were doing it should suggest that it was
intentional. Might want to wait a bit longer while someone dregs up the
history.