[PATCH 0 of 9] libxl: autogenerate type definitions and destructor functions

[Ian Campbell <ian.campbell@citrix.com>]

The series introduces auto-generation of the type definitions used in
the libxl interface followed by auto-generation of a destructor
function for each type. In the future it may be possible to use the
related data structures for other purposes, for example auto-generation
of the functions to marshal between C and language binding data types.

This series complements Gianni Tedesco's "Implement per-API-call
garbage-collection lifetime" patch but doesn't yet tie the two
together with a neat bow.

I have tested with xl create and xl destroy but since the only
practical impact on the running code is in the final patch (which
impacts create only) I think the probabilty of complete carnage are
small (ish).

tools/_libxl_types.h should be identical both before applying and
after applying+building "[PATCH 7 of 9] libxl: autogenerate _libxl_types.h".

Ian.