perf tools: Move event synthesizing routines to separate .c file

For better grouping, in time we may end up making most of these static,
i.e. generalizing the 'perf record' synthesizing code so that based on
the target it can do the right thing and call the needed synthesizers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-s9zxxhk40s95pjng9panet16@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/header.h

@@ -92,6 +92,24 @@ struct perf_header {
 	struct perf_env 	env;
 };
 
+struct feat_fd {
+	struct perf_header *ph;
+	int		   fd;
+	void		   *buf;	/* Either buf != NULL or fd >= 0 */
+	ssize_t		   offset;
+	size_t		   size;
+	struct evsel	   *events;
+};
+
+struct perf_header_feature_ops {
+	int	   (*write)(struct feat_fd *ff, struct evlist *evlist);
+	void	   (*print)(struct feat_fd *ff, FILE *fp);
+	int	   (*process)(struct feat_fd *ff, void *data);
+	const char *name;
+	bool	   full_only;
+	bool	   synthesize;
+};
+
 struct evlist;
 struct perf_session;
 struct perf_tool;