Merge branch 'tb/refs-exclusion-and-packed-refs' into next

Enumerating refs in the packed-refs file, while excluding refs that
match certain patterns, has been optimized.

* tb/refs-exclusion-and-packed-refs:
  ls-refs.c: avoid enumerating hidden refs where possible
  upload-pack.c: avoid enumerating hidden refs where possible
  builtin/receive-pack.c: avoid enumerating hidden references
  refs.h: implement `hidden_refs_to_excludes()`
  refs.h: let `for_each_namespaced_ref()` take excluded patterns
  revision.h: store hidden refs in a `strvec`
  refs/packed-backend.c: add trace2 counters for jump list
  refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)
  refs/packed-backend.c: refactor `find_reference_location()`
  refs: plumb `exclude_patterns` argument throughout
  builtin/for-each-ref.c: add `--exclude` option
  ref-filter.c: parameterize match functions over patterns
  ref-filter: add `ref_filter_clear()`
  ref-filter: clear reachable list pointers after freeing
  ref-filter.h: provide `REF_FILTER_INIT`
  refs.c: rename `ref_filter`

revision.h

@@ -10,6 +10,7 @@
 #include "decorate.h"
 #include "ident.h"
 #include "list-objects-filter-options.h"
+#include "strvec.h"
 
 /**
  * The revision walking API offers functions to build a list of revisions
@@ -95,7 +96,7 @@ struct ref_exclusions {
 	 * Hidden refs is a list of patterns that is to be hidden via
 	 * `ref_is_hidden()`.
 	 */
-	struct string_list hidden_refs;
+	struct strvec hidden_refs;
 
 	/*
 	 * Indicates whether hidden refs have been configured. This is to
@@ -110,7 +111,7 @@ struct ref_exclusions {
  */
 #define REF_EXCLUSIONS_INIT { \
 	.excluded_refs = STRING_LIST_INIT_DUP, \
-	.hidden_refs = STRING_LIST_INIT_DUP, \
+	.hidden_refs = STRVEC_INIT, \
 }
 
 struct oidset;