s390: Add arch15 instructions

opcodes/
	* s390-mkopc.c (main) Accept arch15 as CPU string.
	* s390-opc.txt: Add arch15 instructions.

include/
	* opcode/s390.h (enum s390_opcode_cpu_val): Add
	S390_OPCODE_ARCH15.

gas/
	* config/tc-s390.c (s390_parse_cpu): New entry for arch15.
	* doc/c-s390.texi: Document arch15 march option.
	* doc/as.texi: Likewise.
	* testsuite/gas/s390/s390.exp: Run the arch15 related tests.
	* testsuite/gas/s390/zarch-arch15.d: Tests for arch15
	instructions.
	* testsuite/gas/s390/zarch-arch15.s: Likewise.

Signed-off-by: Andreas Krebbel <krebbel@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
10 files changed