This patch improves the handling of 64-bit parameters in syscalls on ARM.
The ARM EABI mandates that 64-bit quantities be passed in even/odd register
pairs, which requires special treatment.
This allows us to simplify our implementations of pread() and pwrite()
and remove the C stubs for pread64() and pwrite64().
Also add ftruncate64() to <unistd.h>
Change-Id: I407e2fd223ba0093dd2d0b04c6152fadfc9ce3ef
Bug 3107933
