pack: move static state variables

sha1_file.c declares some static variables that store packfile-related
state. Move them to packfile.c.

They are temporarily made global, but subsequent commits will restore
their scope back to static.
Signed-off-by: NJonathan Tan <jonathantanmy@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

packfile.c

 #include "cache.h"
+#include "mru.h"
 
 char *odb_pack_name(struct strbuf *buf,
 		    const unsigned char *sha1,
@@ -21,3 +22,16 @@ char *sha1_pack_index_name(const unsigned char *sha1)
 	static struct strbuf buf = STRBUF_INIT;
 	return odb_pack_name(&buf, sha1, "idx");
 }
+
+unsigned int pack_used_ctr;
+unsigned int pack_mmap_calls;
+unsigned int peak_pack_open_windows;
+unsigned int pack_open_windows;
+unsigned int pack_open_fds;
+unsigned int pack_max_fds;
+size_t peak_pack_mapped;
+size_t pack_mapped;
+struct packed_git *packed_git;
+
+static struct mru packed_git_mru_storage;
+struct mru *packed_git_mru = &packed_git_mru_storage;

packfile.h

@@ -24,4 +24,13 @@ extern char *sha1_pack_name(const unsigned char *sha1);
  */
 extern char *sha1_pack_index_name(const unsigned char *sha1);
 
+extern unsigned int pack_used_ctr;
+extern unsigned int pack_mmap_calls;
+extern unsigned int peak_pack_open_windows;
+extern unsigned int pack_open_windows;
+extern unsigned int pack_open_fds;
+extern unsigned int pack_max_fds;
+extern size_t peak_pack_mapped;
+extern size_t pack_mapped;
+
 #endif

sha1_file.c

@@ -684,19 +684,6 @@ static int has_loose_object(const unsigned char *sha1)
 	return check_and_freshen(sha1, 0);
 }
 
-static unsigned int pack_used_ctr;
-static unsigned int pack_mmap_calls;
-static unsigned int peak_pack_open_windows;
-static unsigned int pack_open_windows;
-static unsigned int pack_open_fds;
-static unsigned int pack_max_fds;
-static size_t peak_pack_mapped;
-static size_t pack_mapped;
-struct packed_git *packed_git;
-
-static struct mru packed_git_mru_storage;
-struct mru *packed_git_mru = &packed_git_mru_storage;
-
 void pack_report(void)
 {
 	fprintf(stderr,