glsl: process bindless/bound layout qualifiers

This adds bindless_sampler and bound_sampler (and respectively
bindless_image and bound_image) to the parser.

v3: - add an extra space in apply_bindless_qualifier_to_variable()
    - fix indentation in merge_qualifier()

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/compiler/glsl/ast.h

@@ -622,6 +622,14 @@ struct ast_type_qualifier {
           * is used.
           */
          unsigned inner_coverage:1;
+
+         /** \name Layout qualifiers for GL_ARB_bindless_texture */
+         /** \{ */
+         unsigned bindless_sampler:1;
+         unsigned bindless_image:1;
+         unsigned bound_sampler:1;
+         unsigned bound_image:1;
+         /** \} */
       }
       /** \brief Set of flags, accessed by name. */
       q;