* include/lightning.h, lib/jit_aarch64.c,
lib/jit_alpha.c, lib/jit_arm-vfp.c, lib/jit_arm.c,
lib/jit_hppa.c, lib/jit_ia64.c, lib/jit_mips.c,
lib/jit_ppc.c, lib/jit_s390.c, lib/jit_sparc.c,
lib/jit_x86.c: Add the new jit_arg_register_p predicate.
The predicate is expected to be used to know if an
argument is in a register, what would need special
handling if code that can overwrite non callee save
registers is executed.
* check/carg.c: New test case to check consistency and
expected usage of jit_arg_register_p.
* check/Makefile.am: Update for new test case.
