st/mesa: fix per-vertex edge flags and GLSL support (v2)

This fixes piglit/gl-2.0-edgeflag.

v2: use StrideB to recognize per-vertex edge flags

Cc: mesa-stable@lists.freedesktop.org
st/mesa: implement zero-stride edge flag by culling primitives

This was unimplemented.
st/mesa: remove _NEW_POLYGON dependency from vertex shader

We can just check the polygon mode when updating the edge flag state.
Also, we can just flag ST_NEW_VERTEX_PROGRAM directly, which makes
ST_NEW_EDGEFLAGS_DATA useless.
radeonsi/compute: Fix memory leak

Free shader buffer object for all kernels when deleting compute state.

Signed-off-by: Aaron Watry <awatry@gmail.com>
mesa: mark GL_RGB9_E5 as not color-renderable

The GL 4.4 spec says it's not color-renderable and not accepted
by RenderBufferStorage. The EXT_texture_shared_exponent spec says
it's not color-renderable but it's accepted by RenderBufferStorageEXT.
This seems to be a bug in the extension spec.

Let's do what GL 4.4 says.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>