mesa: add implementation of glDrawElementsInstancedBaseVertex

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 993519f..2981d42 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -396,7 +396,8 @@
 GLboolean
 _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
                                      GLenum mode, GLsizei count, GLenum type,
-                                     const GLvoid *indices, GLsizei numInstances)
+                                     const GLvoid *indices, GLsizei numInstances,
+                                     GLint basevertex)
 {
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
 
@@ -447,7 +448,7 @@
          return GL_FALSE;
    }
 
-   if (!check_index_bounds(ctx, count, type, indices, 0))
+   if (!check_index_bounds(ctx, count, type, indices, basevertex))
       return GL_FALSE;
 
    return GL_TRUE;