Reorder some khash declarations

Keep the definitions in the headers, while putting the declarations in
the C files. Putting the function definitions in headers causes
them to be duplicated if you include two headers with them.

src/describe.c

@@ -19,6 +19,8 @@
 #include "vector.h"
 #include "repository.h"
 
+GIT__USE_OIDMAP;
+
 /* Ported from https://github.com/git/git/blob/89dde7882f71f846ccd0359756d27bebc31108de/builtin/describe.c */
 
 struct commit_name {

src/indexer.c

@@ -18,6 +18,8 @@
 #include "oidmap.h"
 #include "zstream.h"
 
+GIT__USE_OIDMAP;
+
 extern git_mutex git__mwindow_mutex;
 
 #define UINT31_MAX (0x7FFFFFFF)

src/pack-objects.c

@@ -39,6 +39,8 @@ struct pack_write_context {
 	git_transfer_progress *stats;
 };
 
+GIT__USE_OIDMAP;
+
 #ifdef GIT_THREADS
 
 #define GIT_PACKBUILDER__MUTEX_OP(pb, mtx, op) do { \

src/pack.c

@@ -16,6 +16,9 @@
 
 #include <zlib.h>
 
+GIT__USE_OFFMAP;
+GIT__USE_OIDMAP;
+
 static int packfile_open(struct git_pack_file *p);
 static git_off_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n);
 int packfile_unpack_compressed(

src/pack.h

@@ -71,9 +71,7 @@ struct pack_chain_elem {
 typedef git_array_t(struct pack_chain_elem) git_dependency_chain;
 
 #include "offmap.h"
-
-GIT__USE_OFFMAP
-GIT__USE_OIDMAP
+#include "oidmap.h"
 
 #define GIT_PACK_CACHE_MEMORY_LIMIT 16 * 1024 * 1024
 #define GIT_PACK_CACHE_SIZE_LIMIT 1024 * 1024 /* don't bother caching anything over 1MB */

src/revwalk.c

@@ -14,6 +14,8 @@
 #include "git2/revparse.h"
 #include "merge.h"
 
+GIT__USE_OIDMAP;
+
 git_commit_list_node *git_revwalk__commit_lookup(
 	git_revwalk *walk, const git_oid *oid)
 {

src/revwalk.h

@@ -14,7 +14,7 @@
 #include "pool.h"
 #include "vector.h"
 
-GIT__USE_OIDMAP
+#include "oidmap.h"
 
 struct git_revwalk {
 	git_repository *repo;