glsl/images: bounds check image unit assignment
glsl/images: bounds check image unit assignment

The CTS test:
GL45-CTS.multi_bind.dispatch_bind_image_textures
binds 192 image uniforms, we reject this later,
but not until after we trash the contents of the
struct gl_shader.

Error now reads:
Too many compute shader image uniforms (192 > 16)
instead of
Too many compute shader image uniforms (2745344416 > 16)

Reviewed-by: Ilia Mirkin <bcbbb7aa705ec3a5fc5824c01a845186c3d62fca@alum.mit.edu>
Cc: "12.0" <59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler