fill_stat_cache_info(): prepare for an fsmonitor fix

We will need to pass down the `struct index_state` to
`mark_fsmonitor_valid()` for an upcoming bug fix, and this here function
calls that there function, so we need to extend the signature of
`fill_stat_cache_info()` first.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/cache.h b/cache.h
index b4bb2e2..bf20337 100644
--- a/cache.h
+++ b/cache.h
@@ -826,7 +826,7 @@ int match_stat_data(const struct stat_data *sd, struct stat *st);
 int match_stat_data_racy(const struct index_state *istate,
 			 const struct stat_data *sd, struct stat *st);
 
-void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
+void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st);
 
 #define REFRESH_REALLY		0x0001	/* ignore_valid */
 #define REFRESH_UNMERGED	0x0002	/* allow unmerged */