Merge branch 'bc/c23'

C23 compatibility updates.

* bc/c23:
  reflog: rename unreachable
  index-pack: rename struct thread_local

diff --cc builtin/index-pack.c
index 08b340552f3e92b5c56de24a37fea7413dd2306d,74675dbd6c922134bebce075419c369be1639d83..d8f9360222e1fc9c657b1c534cdfd63e4c6857ab
--- 1/builtin/index-pack.c
--- 2/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@@ -154,14 -148,7 +154,14 @@@ static uint32_t input_crc32
  static int input_fd, output_fd;
  static const char *curr_pack;
  
- static struct thread_local *thread_data;
 +/*
 + * local_links is guarded by read_mutex, and record_local_links is read-only in
 + * a thread.
 + */
 +static struct oidset local_links = OIDSET_INIT;
 +static int record_local_links;
 +
+ static struct thread_local_data *thread_data;
  static int nr_dispatched;
  static int threads_active;