Add unverified_compile_assert

This version of compile_assert is not expanded during verification builds and
can be used in cases where you would like an assertion that contains syntax
that is not supported by the C parser

Add missing include in assert.h

s/DEBUG/CONFIG_DEBUG_BUILD/

DEBUG definition is not supposed to be used in the kernel, rather CONFIG_DEBUG_BUILD,
which can be toggled separately to user notion of DEBUG

Always have compile_assert enabled

A compile assert has no runtime or image size overhead and so there
is no reason to not have them enabled

This commit addresses SELFOUR-289

Release snapshot