Log Message:
Update to xen 4.11.1.
4.11.1 includes all security patches up to XSA282. At this time, no Xen
Security Advisory newer than XSA282 are relevant for xentools411.
changes since 4.11.0 are mostly bugfixes, no new features.
pkgsrc change: drop gcc4.8 requirement, as we're not building the
stub domains binaries it's not needed.