gallium: add new semantic for clip vertex.

This is to match the gl_ClipVertex output from GLSL 1.20.

Signed-off-by: Dave Airlie <airlied@redhat.com>

src/gallium/auxiliary/tgsi/tgsi_strings.c

@@ -71,7 +71,8 @@ const char *tgsi_semantic_names[TGSI_SEMANTIC_COUNT] =
    "INSTANCEID",
    "VERTEXID",
    "STENCIL",
-   "CLIPDIST"
+   "CLIPDIST",
+   "CLIPVERTEX"
 };
 
 const char *tgsi_texture_names[TGSI_TEXTURE_COUNT] =

src/gallium/include/pipe/p_shader_tokens.h

@@ -147,7 +147,8 @@ struct tgsi_declaration_dimension
 #define TGSI_SEMANTIC_VERTEXID   11
 #define TGSI_SEMANTIC_STENCIL    12
 #define TGSI_SEMANTIC_CLIPDIST   13
-#define TGSI_SEMANTIC_COUNT      14 /**< number of semantic values */
+#define TGSI_SEMANTIC_CLIPVERTEX 14
+#define TGSI_SEMANTIC_COUNT      15 /**< number of semantic values */
 
 struct tgsi_declaration_semantic
 {