increase the accuracy of register pressure computation in the presence of dead definitions by using live intervals, if available, to identify dead definitions and proceed accordingly.
Py3k compat for clang-format Sublime Text extension.

Sublime Text 2 uses Python 2.6
Sublime Text 3 uses Python 3.3

The `print` function has been available as a __future__ import since
2.6, so use it.

Patch by Johan Engelen!