[ARM] Cleanup 64-bit multiplies

[ARM] Cleanup 64-bit multiplies

Cleanup 64-bit multiplies.  Combine the expanders using iterators.
Merge the signed/unsigned multiplies as well as the pre-Armv6 and Armv6
variants.  Split DImode operands early into parallel sets inside the
MULL/MLAL instructions - this improves register allocation and avoids
subreg issues due to other DImode operations splitting early.

    gcc/
	* config/arm/arm.md (maddsidi4): Remove expander.
	(mulsidi3adddi): Remove pattern.
	(mulsidi3adddi_v6): Likewise.
	(mulsidi3_nov6): Likewise.
	(mulsidi3_v6): Likewise.
	(umulsidi3): Remove expander.
	(umulsidi3_nov6): Remove pattern.
	(umulsidi3_v6): Likewise.
	(umulsidi3adddi): Likewise.
	(umulsidi3adddi_v6): Likewise.
	(<Us>mulsidi3): Add combined expander.
	(<Us>maddsidi4): Likewise.
	(<US>mull): Add combined umull and smull pattern.
	(<US>mlal): Likewise.
	* config/arm/iterators.md (Us): Add new iterator.

From-SVN: r275901