Merge branch 'cw/maint-exec-defpath'

* cw/maint-exec-defpath:
  autoconf: Check if <paths.h> exists and set HAVE_PATHS_H
  exec_cmd.c: replace hard-coded path list with one from <paths.h>

exec_cmd.c

@@ -107,7 +107,7 @@ void setup_path(void)
 	if (old_path)
 		strbuf_addstr(&new_path, old_path);
 	else
-		strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
+		strbuf_addstr(&new_path, _PATH_DEFPATH);
 
 	setenv("PATH", new_path.buf, 1);