Merge branch 'ep/do-not-feed-a-pointer-to-array-size'

Catch a programmer mistake to feed a pointer not an array to
ARRAY_SIZE() macro, by using a couple of GCC extensions.

* ep/do-not-feed-a-pointer-to-array-size:
git-compat-util.h: implement a different ARRAY_SIZE macro for for safely deriving the size of array

diff --cc git-compat-util.h
Simple merge