Remove the artificial limit on code alignment through the use of the

Remove the artificial limit on code alignment through the use of the
fixed part of a fragment for output generation only, which required
MAX_MEM_FOR_RS_ALIGN_CODE to be large enough to hold the maximum pad.

	* config/tc-aarch64.h (MAX_MEM_FOR_RS_ALIGN_CODE): Define to 7.
	* config/tc-aarch64.c (aarch64_handle_align): Rewrite to handle
	large alignments with a constant fragment size of
	MAX_MEM_FOR_RS_ALIGN_CODE.