nv2a: Improve some assert messages

Author: abaire

hw/xbox/nv2a/pgraph/pgraph.c

@@ -3063,7 +3063,7 @@ void pgraph_get_clear_color(PGRAPHState *pg, float rgba[4])
         *b = 1.0f;
         fprintf(stderr, "CLEAR_SURFACE for color_format 0x%x unsupported",
                 pg->surface_shape.color_format);
-        assert(false);
+        assert(!"CLEAR_SURFACE not supported for selected surface format");
         break;
     }
 
@@ -3077,7 +3077,7 @@ void pgraph_get_clear_color(PGRAPHState *pg, float rgba[4])
     case NV097_SET_SURFACE_FORMAT_COLOR_LE_X1A7R8G8B8_Z1A7R8G8B8:
     case NV097_SET_SURFACE_FORMAT_COLOR_LE_X1A7R8G8B8_O1A7R8G8B8:
         *a = ((clear_color >> 24) & 0x7F) / 127.0f;
-        assert(false); /* Untested */
+        assert(!"CLEAR_SURFACE handling for LE_X1A7R8G8B8_Z1A7R8G8B8 and LE_X1A7R8G8B8_O1A7R8G8B8 is untested"); /* Untested */
         break;
     case NV097_SET_SURFACE_FORMAT_COLOR_LE_A8R8G8B8:
         *a = ((clear_color >> 24) & 0xFF) / 255.0f;