Bug#978401: ibus-libpinyin: FTBFS on armel, armhf and mipsel: lua test failure

[Gunnar Hjalmarsson <gunnarhj@debian.org>]

At last lua5.4 is included in Ubuntu's main, so I'm preparing the source 
for being suitable for Ubuntu to sync.

* As a first step I tried an upload to experimental with lua support 
enabled on all archs. So far it has refused to build on the particular 
archs I'm interested in (armhf and armel), though.

* If it would fail on any of those archs, I plan to enable LTO in the 
package. The rationale for that is that it builds fine in Ubuntu on 
armhf also with lua5.4 support, and Ubuntu builds with LTO enabled.

* As a last resort, if the armhf build still fails due to lua, I'm 
thinking of a conditional in d/rules rather than changing b-d in 
d/control, so we can distinguish between Debian and Ubuntu in this respect.

Please let me know if you have any doubts.

--
Gunnar