mesa: add support for GL_INTEL_conservative_rasterization

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>

src/compiler/glsl/ast.h

@@ -610,6 +610,11 @@ struct ast_type_qualifier {
           * Flag set if GL_ARB_post_depth_coverage layout qualifier is used.
           */
          unsigned post_depth_coverage:1;
+         /**
+          * Flag set if GL_INTEL_conservartive_rasterization layout qualifier
+          * is used.
+          */
+         unsigned inner_coverage:1;
       }
       /** \brief Set of flags, accessed by name. */
       q;