Add a patch setting by default flags to optimize the binary size

• Add "lto": whole binary link time optimisation.
• Use opt-level = "z": to optimize for size.
• Make the panic handler simply abort() rather then unwinding and printing a backtrace.

Add flag in debian/rules to strip symbols from the binary.

Inspired by https://github.com/uutils/coreutils/commit/0c4f586

Signed-off-by: Detlev Casanova detlev.casanova@collabora.com Signed-off-by: Sjoerd Simons sjoerd@collabora.com Signed-off-by: Dylan Aïssi dylan.aissi@collabora.com