mesa/st, iris, rusticl: Add cl_khr_gl_sharing extension
This MR adds the following:
- Implementation of gl_sharing in rusticl, which includes:
- Being able to create a cl context using a gl one
- Being able to create cl memory objects from gl ones. (buffers, textures, cubemaps, and renderbuffers)
- acquire_gl_objects and release_gl_objects functions with explicit synchronization
- Add, again, support for PIPE_BUFFER in resource_from_handle in iris
Signed-off-by: Antonio Gomes antoniospg100@gmail.com