Disable chdir in execute fuzzers

We don't want the current working directory to change during
fuzzing, as that breaks corpus access unless an absolute path is
used. I'm not sure why this issue never came up before.

Author: nikic

sapi/fuzzer/fuzzer-sapi.c

@@ -47,7 +47,7 @@ const char HARDCODED_INI[] =
 	"open_basedir=/tmp\n"
 	"disable_functions=dl,mail,mb_send_mail"
 	",shell_exec,exec,system,proc_open,popen,passthru,pcntl_exec"
-	",chgrp,chmod,chown,copy,file_put_contents,lchgrp,lchown,link,mkdir"
+	",chdir,chgrp,chmod,chown,copy,file_put_contents,lchgrp,lchown,link,mkdir"
 	",move_uploaded_file,rename,rmdir,symlink,tempname,touch,unlink,fopen"
 	/* Networking code likes to wait and wait. */
 	",fsockopen,pfsockopen"