arm: elide some cases where the AES erratum workaround is not required.

arm: elide some cases where the AES erratum workaround is not required.

Some common cases where the AES erratum workaround are not required
are when there are 64- or 128-bit loads from memory, moving a 128-bit
value from core registers, and where a 128-bit constant is being
loaded from a literal pool.  The loads may also be misaligned or
generated via a neon intrinsic function.

gcc/ChangeLog:

	* config/arm/crypto.md (aes_op_protect): Allow moves from core
	registers and from memory.
	(aes_op_protect_misalign_load): New pattern.
	(aes_op_protect_neon_vld1v16qi): New pattern.