Log Message:
Update xenkernel415 and xentools415 to 4.15.1.
32bits PV guests are now unsupported security-wise, and upstream disables
them by default. This packages keep the support enabled for transition, but
this will change for the next quarter branch. It is recommended to switch to
pvh+pvshim for PV guests (or pvh if you run netbsd-current).
Other changes are bugfixes, including fixes for XSA up to XSA-384