ARMv8 adds new VCVT variants, VCVT[ANPM] to A32 and T32.

This patch adds support for them.

gas/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* config/tc-arm.c (NEON_ENC_TAB): Add vcvta entry.
	(neon_cvt_mode): New enumeration.
	(do_vfp_nsyn_cvt_fpv8): New function.
	(do_neon_cvt_1): Add support for new conversions.
	(do_neon_cvtr): Use neon_cvt_mode enumerator.
	(do_neon_cvt): Likewise.
	(do_neon_cvta): New function.
	(do_neon_cvtn): Likewise.
	(do_neon_cvtp): Likewise.
	(do_neon_cvtm): Likewise.
	(insns): Add new VCVT instructions.

gas/testsuite/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* gas/arm/armv8-a+fp.d: Update testcase.
	* gas/arm/armv8-a+fp.s: Likewise.
	* gas/arm/armv8-a+simd.d: Likewise.
	* gas/arm/armv8-a+simd.s: Likewise.

opcodes/ChangeLog:
2012-08-23  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>

	* arm-dis.c (coprocessor_opcodes): Add support for new VCVT
	variants.
	(neon_opcodes): Likewise.