This requires nuttx/pull/11548 to work.
- Zig apps can use normal entrance "main()" now as we
- added RENAMEMAIN for none BUILD_MODULE case.
- enabled Zig program building in BUILD_MODULE case.
Note the Zig main source need to have "fn main(" pattern as
renaming is implemented via `sed`.
Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>
