run php-src/Zend/bench.php coredump #38

test code is: https://github.com/php/php-src/blob/php-7.0.33/Zend/bench.php
It looks like an infinite loop
The stack：
(gdb) bt
#0 0x0000000000ba46e3 in xbuf_format_converter ()
#1 0x0000000000ba70bc in php_printf_to_smart_string ()
#2 0x0000000000c73d9b in zend_vspprintf ()
#3 0x0000000000c73ec3 in zend_spprintf ()
#4 0x00007f2b8407f9b0 in hp_get_function_name (execute_data=0x7f2b83eed720) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:672
#5 hp_execute_ex (execute_data=0x7f2b83eed720) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1116
#6 0x0000000000e08947 in execute_ex ()
#7 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eed620) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#8 0x0000000000e08947 in execute_ex ()
#9 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eed420) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#10 0x0000000000e08947 in execute_ex ()
#11 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eed220) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#12 0x0000000000e08947 in execute_ex ()
#13 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eed020) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#14 0x0000000000e08947 in execute_ex ()
#15 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eece20) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#16 0x0000000000e08947 in execute_ex ()
#17 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eecc20) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#18 0x0000000000e08947 in execute_ex ()
#19 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eeca20) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#20 0x0000000000e08947 in execute_ex ()
#21 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eec820) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#22 0x0000000000e08947 in execute_ex ()
#23 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eec620) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#24 0x0000000000e08947 in execute_ex ()
#25 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eec420) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#26 0x0000000000e08947 in execute_ex ()
#27 0x00007f2b8407f89d in hp_execute_ex (execute_data=0x7f2b83eec220) at /home/liushuai/git_dir/baidu/third-party/php-extensions/.tmp/php7.0/xhprof/src/xhprof.c:1127
#28 0x0000000000e08947 in execute_ex ()