headers: crt: split out corecrt_malloc.h

memalignment is kept in stdlib.h, as this is part of ISO C23, and MSVC
doesn't provide it.

Also remove _CRT_ALLOCATION_DEFINED.

Signed-off-by: Zhongteng Gui <dragon-archer@outlook.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>
3 files changed