[ARC] Check for odd-even register when emitting double mac ops.

[ARC] Check for odd-even register when emitting double mac ops.

gcc/
	Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.md (maddsidi4_split): Don't use dmac if the
	destination register is not odd-even.
	(umaddsidi4_split): Likewise.

gcc/testsuite/
	Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/tmac-3.c: New file.

From-SVN: r264736