Merge branch 'jc/make-static'

Merge branch 'jc/make-static'

Turn many file-scope private symbols to static to reduce the
global namespace contamination.

* jc/make-static:
  sequencer.c: mark a private file-scope symbol as static
  ident.c: mark private file-scope symbols as static
  trace.c: mark a private file-scope symbol as static
  wt-status.c: mark a private file-scope symbol as static
  read-cache.c: mark a private file-scope symbol as static
  strbuf.c: mark a private file-scope symbol as static
  sha1-array.c: mark a private file-scope symbol as static
  symlinks.c: mark private file-scope symbols as static
  notes.c: mark a private file-scope symbol as static
  rerere.c: mark private file-scope symbols as static
  graph.c: mark private file-scope symbols as static
  diff.c: mark a private file-scope symbol as static
  commit.c: mark a file-scope private symbol as static
  builtin/notes.c: mark file-scope private symbols as static