Comment 4 for bug 1703250

I was interested how everything behaves and got avr-gcc 5.4 to work on OpenSuse Tumbleweed (my main Distro) so here are tests with 5.4 and biscotti:

OpenSuse Tumbleweed GCC 5.4

no extern
-std=gnu11 1020 bytes
-std=gnu99 1020 bytes
-std=gnu89 1082 bytes
-std=gnu11 -fgnu11-inline 1082 bytes
-std=gnu99 -fgnu99-inline 1082 bytes
-std=gnu89 -fgnu89-inline 1082 bytes
extern inline
-std=gnu11 1078 bytes
-std=gnu99 1078 bytes
-std=gnu89 1024 bytes
-std=gnu11 -fgnu89-inline 1024 bytes
-std=gnu99 -fgnu89-inline 1024 bytes
-std=gnu89 -fgnu89-inline 1024 bytes

And as I have the VM up and running, here are the 7.1 results on arch:
no extern
-std=gnu11 fails
-std=gnu99 fails
-std=gnu89 1082 bytes
-std=gnu89 -fgnu11-inline 1082 bytes
-std=gnu89 -fgnu99-inline 1082 bytes
-std=gnu89 -fgnu89-inline 1082 bytes
extern inline
-std=gnu11 1078 bytes
-std=gnu99 1078 bytes
-std=gnu89 1026 bytes
-std=gnu11 -fgnu89-inline 1026 bytes
-std=gnu99 -fgnu89-inline 1026 bytes
-std=gnu89 -fgnu89-inline 1026 bytes

Both times avr-libc 2.0

I'll see how easy it is to update GCC to 6 and 7 on TW (it is a different repo and has problems) and will add results in case it works.