[AArch64] Restrict usage of FP/SIMD registers for TImode reload and absdi2 patterns...

[AArch64] Restrict usage of FP/SIMD registers for TImode reload and absdi2 patterns for non-float/simd targets.

	* config/aarch64/aarch64.md (absdi2): Set simd attribute.
	(aarch64_reload_mov<mode>): Predicate on TARGET_FLOAT.
	(aarch64_movdi_<mode>high): Likewise.
	(aarch64_mov<mode>high_di): Likewise.
	(aarch64_movdi_<mode>low): Likewise.
	(aarch64_mov<mode>low_di): Likewise.
	(aarch64_movtilow_tilow): Likewise.
	Add comment explaining usage of fp,simd attributes and of
	TARGET_FLOAT and TARGET_SIMD.

From-SVN: r213712