[PATCH 0/3] glamor: Disable shader-based trapezoids. Bug 76213.

[Keith Packard]

The shader-based trapezoid drawing code in glamor draws incorrectly
and doesn't appear to offer any performance benefits. This series
fixes a couple of compiler warning problems and then disables the
shader based trapezoid code.

This fixes the bottom and right shadows in the XFCE panel when drawn
with system style as seen in this bug report:

https://bugs.freedesktop.org/show_bug.cgi?id=76213