Makefile: add a new script to check -fstack-usage support

If -fstack-usage option is given to crosstools
that do not support it, gcc displays a warning message
but still exits with status 0.

This means we can not rely on $(call cc-option,...)
to detect if -fstack-usage option is supported or not.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>