Merge branch 'jc/diff-test-updates' into maint

Test clean-up.

* jc/diff-test-updates:
  test_ln_s_add: refresh stat info of fake symbolic links
  t4008: modernise style
  t/diff-lib: check exact object names in compare_diff_raw
  tests: do not borrow from COPYING and README from the real source
  t4010: correct expected object names
  t9300: correct expected object names
  t4008: correct stale comments

diff --cc t/t4005-diff-rename-2.sh
Simple merge

diff --cc t/t4009-diff-rename-4.sh
Simple merge

diff --cc t/t4010-diff-pathspec.sh
Simple merge

diff --cc t/t9300-fast-import.sh
Simple merge

diff --cc t/test-lib-functions.sh
Simple merge