Make a build comaprsion with SDK-5.1 and sdk-5.2.
The image built with SDK-5.2 is much bigger than the image built with SDK-5.1.
e.g. use test.console with LwIP build as example,
On SDK-5.2: the image size: 412028
On SDK-5.1: the image size: 365100
The diff is about 45KB.
(Note, I already disable IPV6 in SDK-5.2 for the build comparison).
Such image size increasing is a surprise again.
