libxl: include <_libxl_paths.h> in libxl_internal.h

Ie, we permit general code in libxl direct access to the manifest
constants such as XEN_RUN_DIR.  This simplifies their use in (eg)
format strings.

This might be controversial because it will make it difficult to make
any of these runtime-configurable later without changing lots of use
sites.  But I don't think it's likely we'll want to do that.

For the moment, leave existing call sites of all the functions in
libxl_paths.c unchanged.  The simplified use arrangements can be used
in new code and when we update call sites for other reasons.

Also correct the dependencies in the Makefile so that _libxl_paths.h
is generated before anything that uses libxl_internal.h.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Roger Pau Monne <roger.pau@entel.upc.edu>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

tools/libxl/Makefile

@@ -102,11 +102,9 @@ _libxl_list.h: $(XEN_INCLUDE)/xen-external/bsd-sys-queue-h-seddery $(XEN_INCLUDE
 	perl $^ --prefix=libxl >$@.new
 	$(call move-if-changed,$@.new,$@)
 
-libxl_paths.c: _libxl_paths.h
-
 libxl.h: _libxl_types.h
 libxl_json.h: _libxl_types_json.h
-libxl_internal.h: _libxl_types_internal.h
+libxl_internal.h: _libxl_types_internal.h _libxl_paths.h
 libxl_internal_json.h: _libxl_types_internal_json.h
 
 $(LIBXL_OBJS) $(LIBXLU_OBJS) $(XL_OBJS): libxl.h

tools/libxl/libxl_internal.h

@@ -51,6 +51,7 @@
 #include <xen/io/xenbus.h>
 
 #include "libxl.h"
+#include "_libxl_paths.h"
 
 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 #define _hidden __attribute__((visibility("hidden")))

tools/libxl/libxl_paths.c

@@ -14,7 +14,6 @@
 
 #include "libxl_osdeps.h" /* must come before any other headers */
 #include "libxl_internal.h"
-#include "_libxl_paths.h"
 
 const char *libxl_sbindir_path(void)
 {