arm.c (arm_override_options): Add unaligned_access support.

arm.c (arm_override_options): Add unaligned_access support.

	gcc/
	* config/arm/arm.c (arm_override_options): Add unaligned_access
	support.
	(arm_file_start): Emit attribute for unaligned access as
	appropriate.
	* config/arm/arm.md (UNSPEC_UNALIGNED_LOAD)
	(UNSPEC_UNALIGNED_STORE): Add constants for unspecs.
	(insv, extzv): Add unaligned-access support.
	(extv): Change to expander. Likewise.
	(extzv_t1, extv_regsi): Add helpers.
	(unaligned_loadsi, unaligned_loadhis, unaligned_loadhiu)
	(unaligned_storesi, unaligned_storehi): New.
	(*extv_reg): New (previous extv implementation).
	* config/arm/arm.opt (munaligned_access): Add option.
	* config/arm/constraints.md (Uw): New constraint.
	* expmed.c (store_bit_field_1): Adjust bitfield numbering according
	to size of access, not size of unit, when BITS_BIG_ENDIAN !=
	BYTES_BIG_ENDIAN. Don't use bitfield accesses for
	volatile accesses when -fstrict-volatile-bitfields is in effect.
	(extract_bit_field_1): Likewise.

From-SVN: r178852