[klibc] Restructure the FILE object to allow simple inlines

Restructure the FILE object so that functions which are simple
accessors for the FILE object contents can get it from there,
without unnecessarily exposing the internals.  Furthermore,
allocate the buffer and the file object in the same allocation;
no need to have extra mallocs() for no reason.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
18 files changed