shader: Do some basic sanity checks in emit_ios and return early on failure
Allows to just reject the shader in case the provided shader is corrupted.
Closes https://gitlab.freedesktop.org/virgl/virglrenderer/-/issues/354
Allows to just reject the shader in case the provided shader is corrupted.
Closes https://gitlab.freedesktop.org/virgl/virglrenderer/-/issues/354