S/390: arch12: Support the mul/add/subtract

S/390: arch12: Support the mul/add/subtract
 instructions.

gcc/ChangeLog:

2017-03-24  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* config/s390/s390.md ("*adddi3_sign", "*subdi3_sign", "mulditi3")
	("mulditi3_2", "*muldi3_sign"): New patterns.
	("muldi3", "*muldi3", "mulsi3", "*mulsi3"): Add an expander and
	rename the pattern definition.

gcc/testsuite/ChangeLog:

2017-03-24  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* gcc.target/s390/arch12/aghsghmgh-1.c: New test.
	* gcc.target/s390/arch12/mul-1.c: New test.
	* gcc.target/s390/arch12/mul-2.c: New test.

From-SVN: r246457