[RFA] enum enable

[Jim Blandy]

Oh, I hadn't seen this message from Andrew:

Andrew Cagney <ac131313@cygnus.com> writes:
> My preference is for memattr.c to use ``int enabled_p'' and for 
> breakpoint.h to use something like ``enum bp_state { bp_enabled, ...''.

Anyway, I get compilation errors with your patch.  There are uses of
the old struct tracepoint `enabled' member that your patch didn't
catch.

(Or I botched appyling the patch.)