svg: Unwrap recording surfaces

As a first step towards bring SVG uptodate with the various new
patterns, first we need to prevent SVG crashing when it mishandles an
unknown recording surface.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
xml: Handle clip-boxes in the updated cairo_clip_t

Edward Zimmerman pointed out that the xml surface had bitrotted slightly
and no longer understand the new clip layout - in particular that we can
have clips without a path, but just with boxes instead.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
cairo-perf-print: Do not free the uninitialised histogram

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
test: Use the highest precision rendering for shapes for generating ref results

The test-traps and test-base surfaces are used for generating the
reference results, and so they should opt for using the best rendering
paths through the traps- and base-compositors.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
check: Fix check-def.sh for variations in GCC's linker

We now need to exclude bss and data sections from the symbol list.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>