mesa: add storage_count field to GLvector4f. Useful for debugging.

src/mesa/math/m_vector.c

@@ -102,6 +102,7 @@ _mesa_vector4f_alloc( GLvector4f *v, GLuint flags, GLuint count,
    v->stride = 4 * sizeof(GLfloat);
    v->size = 2;
    v->storage = ALIGN_MALLOC( count * 4 * sizeof(GLfloat), alignment );
+   v->storage_count = count;
    v->start = (GLfloat *) v->storage;
    v->data = (GLfloat (*)[4]) v->storage;
    v->count = 0;

src/mesa/math/m_vector.h

@@ -67,6 +67,7 @@ typedef struct {
    GLuint size;		/**< 2-4 for vertices and 1-4 for texcoords */
    GLuint flags;	/**< which columns are dirty */
    void *storage;	/**< self-allocated storage */
+   GLuint storage_count; /**< storage size in elements */
 } GLvector4f;