glsl: Handle the binding qualifier for arrays of samplers.

glsl: Handle the binding qualifier for arrays of samplers.

Normally, uniform array variables are initialized by array literals.
That is, val->type->array_elements >= storage->array_elements.

However, samplers are different.  Consider a declaration such as:

   layout(binding = 5) uniform sampler2D[3];

The initializer value is a single integer (5), while the storage has 3
array elements.  The proper behavior here is to increment one for each
element; they should be initialized to 5, 6, and 7.

This patch introduces new code for sampler types which handles both
arrays of samplers and single samplers correctly.

v2: Move into the other function; use binding, not constant_value.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Paul Berry <stereotype441@gmail.com>