This lets us move all the ARM syscall stubs over to the kernel <asm/unistd.h>.
Our generated <sys/linux-syscalls.h> is now unused, but I'll remove that in a
later change.
Change-Id: Ie5ff2cc4abce1938576af7cbaef615a79c7f310d
Used the new gensyscalls.py script to update the ARM syscalls with the
BEGIN(x) and END(x) macros to give size information for the code of the
syscall. Useful for valgrind.
Change-Id: I8c481c8928401ac110fd19b087f7d67e4db39326
Only provide an implementation for ARM at the moment, since
it requires specific assembly fragments (the standard syscall
stubs cannot be used because the child returns in a different
stack).