Sending LTO delta to Debian

[Andreas Hasenack]

Hi,

this came up again in a review, and I wanted to ask a broader audience.

How to we send LTO[1] related delta to Debian, given that Debian isn't
using LTO (yet)?

Case in point was the ust package[2], which has this bit[3] part of
the delta (just showing the first hunk):
@@ -1,5 +1,5 @@
 liblttng-ust-python-agent.so.1 liblttng-ust-python-agent1 #MINVER#
 * Build-Depends-Package: liblttng-ust-dev
- __start_lttng_ust_tracepoints_ptrs at Base 2.13.0
- __stop_lttng_ust_tracepoints_ptrs at Base 2.13.0
+ (optional=lto)__start_lttng_ust_tracepoints_ptrs at Base 2.13.0
+ (optional=lto)__stop_lttng_ust_tracepoints_ptrs at Base 2.13.0

Is this upstreamable to Debian as is? I know this depends most of the
time on the maintainer, but in general what would be our arguments?
Does it change the behavior of package building when lto is not used?
In a non-lto case, would the disappearance of those symbols be caught?

1. https://wiki.ubuntu.com/ToolChain/LTO
2. https://launchpad.net/ubuntu/+source/ust
3. https://git.launchpad.net/ubuntu/+source/ust/commit/?id=438c8ae30797d92cacc9d0e041a92583fbd5f09d