* gas/config/tc-arm.c (arm_ext_mp): Add.

	* gas/config/tc-arm.c (arm_ext_mp): Add.
	(do_pld): Update comment.
	(insns): Add support for pldw.
	(arm_cpus): Update cortex-a5, cortex-a9, and cortex-a15 to support
	MP extension.
	(arm_extensions): Add 'mp' extension.
	(aeabi_set_public_attributes): Emit correct build attribute when
	MP extension is enabled.
	* gas/doc/c-arm.texi: Update for MP extensions.
	* gas/testsuite/gas/arm/arch7a-mp.d: Add.
	* gas/testsuite/gas/arm/arch7ar-mp.s: Likewise.
	* gas/testsuite/gas/arm/arch7r-mp.d: Likewise.
	* gas/testsuite/gas/arm/armv2-mp-bad.d: Likewise.
	* gas/testsuite/gas/arm/armv2-mp-bad.l: Likewise.
	* gas/testsuite/gas/arm/attr-march-all.d: Update for MP extension.
	* gas/testsuite/gas/arm/attr-march-armv7-a+mp.d: Add.
	* gas/testsuite/gas/arm/attr-march-armv7-r+mp.d: Likewise.
	* include/opcode/arm.h (ARM_EXT_MP): Add.
	(ARM_ARCH_V7A_MP): Likewise.
	* opcodes/arm-dis.c (arm_opcodes): Add support for pldw.
	(thumb32_opcodes): Likewise.