Merge branch 'md/exclude-promisor-objects-fix'

Operations on promisor objects make sense in the context of only a
small subset of the commands that internally use the revisions
machinery, but the "--exclude-promisor-objects" option were taken
and led to nonsense results by commands like "log", to which it
didn't make much sense.  This has been corrected.

* md/exclude-promisor-objects-fix:
  exclude-promisor-objects: declare when option is allowed
  Documentation/git-log.txt: do not show --exclude-promisor-objects

builtin/prune.c

@@ -120,6 +120,7 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 	save_commit_buffer = 0;
 	read_replace_refs = 0;
 	ref_paranoia = 1;
+	revs.allow_exclude_promisor_objects_opt = 1;
 	repo_init_revisions(the_repository, &revs, prefix);
 
 	argc = parse_options(argc, argv, prefix, options, prune_usage, 0);