glsl: ir_texture add clamp field

For ARB_sparse_texture_clamp to hold the lodClamp parameter.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14488>

src/compiler/glsl/ir_equals.cpp

@@ -152,6 +152,9 @@ ir_texture::equals(const ir_instruction *ir, enum ir_node_type ignore) const
    if (!possibly_null_equals(offset, other->offset, ignore))
       return false;
 
+   if (!possibly_null_equals(clamp, other->clamp, ignore))
+      return false;
+
    if (!sampler->equals(other->sampler, ignore))
       return false;