parser: add include dedup cache to handle include loops

Profile includes can be setup to loop and expand in a pathalogical
manner that causes build failures. Fix this by caching which includes
have already been seen in a given profile context.

In addition this can speed up some profile compiles, that end up
re-including common abstractions. By not only deduping the files
being included but skipping the need to reprocess and dedup the
rules within the include.

Fixes: https://bugzilla.suse.com/show_bug.cgi?id=1184779
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/743
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve.beattie@canonical.com>

parser/parser_common.c

@@ -20,6 +20,7 @@
 #include <stdarg.h>
 
 #include "parser.h"
+#include "file_cache.h"
 
 /* Policy versioning is determined by a combination of 3 values:
  * policy_version:     version of txt policy
@@ -95,6 +96,8 @@ char *current_filename = NULL;
 
 FILE *ofile = NULL;
 
+IncludeCache_t *g_includecache;
+
 #ifdef FORCE_READ_IMPLIES_EXEC
 int read_implies_exec = 1;
 #else