This removes the long_long_align_bit gdbarch attribute in favor of
type_align. This uncovered two possible issues.
First, arc-tdep.c claimed that long long alignment was 32 bits, but as
discussed on the list, ARC has a maximum alignment of 32 bits, so I've
added an arc_type_align function to account for this.
Second, jit.c, the sole user of long_long_align_bit, was confusing
"long long" with uint64_t. The relevant structure is defined in the
JIT API part of the manual as: