[sanitizer] Split platform_limits_posix into system- and kernel-dependent parts.

This change moves everything depending on kernel headers (mostly ioctl types
and ids) into a separate source file. This will reduce the possibility of
header conflict on various platforms (most importantly, older glibc versions).

This change also removes 2 deprecated ioctls, and symbolic ids for other bunch
of ambiguous ioctls (i.e. same id is shared by ioctls with different memory
behavior).

llvm-svn: 188369