gallium: Add st_api::name.

It is the name of the rendering API.  This field is informative.

src/gallium/include/state_tracker/st_api.h

@@ -401,6 +401,11 @@ struct st_manager
  */
 struct st_api
 {
+   /**
+    * The name of the rendering API.  This is informative.
+    */
+   const char *name;
+
    /**
     * The supported rendering API.
     */

src/gallium/state_trackers/vega/Makefile

@@ -9,6 +9,9 @@ LIBRARY_INCLUDES = \
 	-I$(TOP)/include \
 	-I$(TOP)/src/mapi
 
+LIBRARY_DEFINES = \
+	-DVEGA_VERSION_STRING=\"$(MESA_VERSION)\"
+
 C_SOURCES = \
            api.c           \
            api_context.c   \

src/gallium/state_trackers/vega/SConscript

@@ -8,6 +8,9 @@ env = env.Clone()
 env.Append(CPPPATH = [
     '#/src/mapi',
 ])
+env.Append(CPPDEFINES = [
+    'VEGA_VERSION_STRING=',
+])
 
 vega_sources = [
     'api.c',

src/gallium/state_trackers/vega/vg_manager.c

@@ -535,6 +535,7 @@ vg_api_destroy(struct st_api *stapi)
 }
 
 static const struct st_api vg_api = {
+   "Vega " VEGA_VERSION_STRING,
    ST_API_OPENVG,
    ST_PROFILE_DEFAULT_MASK,
    vg_api_destroy,

src/mesa/state_tracker/st_manager.c

@@ -865,6 +865,7 @@ st_manager_add_color_renderbuffer(struct st_context *st, struct gl_framebuffer *
 }
 
 static const struct st_api st_gl_api = {
+   "Mesa " MESA_VERSION_STRING,
    ST_API_OPENGL,
 #if FEATURE_GL
    ST_PROFILE_DEFAULT_MASK |