Usage:
1. CONFIG_FS_PROCFS_MAX_STACK_RECORD > 0, such as 32,
2. add '-finstrument-functions' to CFLAGS for What you want to check
stack.
3. mount porcfs
4. cat /proc/<pid>/stack will print backtace & size
Signed-off-by: anjiahao <anjiahao@xiaomi.com>