[Gm2] Build of gm2-5.4.0 on ARM under Ubuntu Mate

[John Dubery]

Gaius,
Back in July I built this version of gm2 on a Raspberry Pi 3 but under 
Ubuntu Mate not Raspbian.  The o/s is 32b not 64b.  Check-gm2 looks very 
good:

         === gm2 Summary ===


# of expected passes        10406
# of unexpected failures    18
# of unresolved testcases    6


I found that I now needed libpth (portable threads library) - should 
this dependency be added to your website?

An interesting difference from Raspbian is that I didn't need to alter 
the toolchain.  I didn't need to link the 3 C start-up files: crt?.o, 
nor the directories in /usr/include/arm-linux-gnueabihf: asm, bits, gnu, 
sys.

BTW, I found that genautomata needs the biggest amount of memory. The 
RPi3 has 1Gb but this function also needed 700Mb of swap.

Regards,
John