Merge branch 'rs/realloc-array'

Code cleanup.

* rs/realloc-array:
use REALLOC_ARRAY for changing the allocation size of arrays
add macro REALLOC_ARRAY

diff --cc builtin/for-each-ref.c
Simple merge

diff --cc builtin/index-pack.c
Simple merge

diff --cc builtin/log.c
Simple merge

diff --cc builtin/merge.c
Simple merge

diff --cc cache.h
Simple merge

diff --cc fast-import.c
Simple merge

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

diff --cc git.c
Simple merge

diff --cc graph.c
Simple merge

diff --cc object.c
Simple merge