perf sort: Remove needless headers from sort.h, provide fwd struct decls

Reducing the includes hell a bit more, speeding up the build and
avoiding needless rebuilds when just one of those files gets updated.

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-u63el2vqsovsmnhebx1rcixo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/callchain.c

@@ -20,6 +20,7 @@
 
 #include "asm/bug.h"
 
+#include "debug.h"
 #include "hist.h"
 #include "sort.h"
 #include "machine.h"

tools/perf/util/sort.h

@@ -1,29 +1,18 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __PERF_SORT_H
 #define __PERF_SORT_H
-#include "../builtin.h"
-
 #include <regex.h>
-
-#include "color.h"
+#include <stdbool.h>
 #include <linux/list.h>
-#include "cache.h"
 #include <linux/rbtree.h>
 #include "map_symbol.h"
 #include "symbol_conf.h"
-#include "string.h"
 #include "callchain.h"
 #include "values.h"
 
-#include "../perf.h"
-#include "debug.h"
-#include "header.h"
-
-#include <subcmd/parse-options.h>
-#include "parse-events.h"
 #include "hist.h"
-#include "srcline.h"
 
+struct option;
 struct thread;
 
 extern regex_t parent_regex;