lib/guestfs-internal.h: Remove need to include gnulib "hash.h" here.

Centrally including "hash.h" means everything that needs this header
file (everything in lib/) has to depend on gnulib.

lib/guestfs-internal.h

@@ -37,6 +37,13 @@
 
 #include <pthread.h>
 
+#include "guestfs-utils.h"
+
+/* Defined in gnulib "hash.h", but we explicitly define it here to
+ * avoid having to include that header everywhere.
+ */
+typedef struct hash_table Hash_table;
+
 /* Minimum required version of libvirt for the libvirt backend.
  *
  * This is also checked at runtime because you can dynamically link
@@ -56,10 +63,6 @@
 #endif
 #endif
 
-#include "hash.h"
-
-#include "guestfs-utils.h"
-
 #if ENABLE_PROBES
 #include <sys/sdt.h>
 /* NB: The 'name' parameter is a literal identifier, NOT a string! */

lib/handle.c

@@ -31,6 +31,7 @@
 #include <libxml/parser.h>
 #include <libxml/xmlversion.h>
 
+#include "hash.h"
 #include "ignore-value.h"
 #include "c-ctype.h"
 #include "getprogname.h"