Merge branch 'az/tighten-string-array-constness'

Code clean-up.

* az/tighten-string-array-constness:
  global: mark usage strings and string tables const

diff --cc builtin/blame.c
Simple merge

diff --cc builtin/commit-graph.c
Simple merge

diff --cc builtin/fast-export.c
Simple merge

diff --cc builtin/mktree.c
Simple merge

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

diff --cc builtin/show-branch.c
Simple merge

diff --cc t/helper/test-pack-mtimes.c
Simple merge