arc/nps400 : New cmem instructions and associated relocation

arc/nps400 : New cmem instructions and associated relocation

Add support for arc/nps400 cmem instructions, these load and store
instructions are hard-wired to access "0x57f00000 + 16-bit-offset".

Supporting this relocation required some additions to the arc relocation
handling in the bfd library, as well as the standard changes required to
add a new relocation type.

There's a test of the new instructions in the assembler, and a test of
the relocation in the linker.

bfd/ChangeLog:

	* reloc.c: Add BFD_RELOC_ARC_NPS_CMEM16 entry.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
	* elf32-arc.c: Add 'opcode/arc.h' include.
	(struct arc_relocation_data): Add symbol_name.
	(arc_special_overflow_checks): New function.
	(arc_do_relocation): Use arc_special_overflow_checks, reindent as
	required, add an extra comment.
	(elf_arc_relocate_section): Setup symbol_name in reloc_data.

gas/ChangeLog:

	* testsuite/gas/arc/nps400-3.d: New file.
	* testsuite/gas/arc/nps400-3.s: New file.

include/ChangeLog:

	* elf/arc-reloc.def: Add ARC_NPS_CMEM16 reloc.
	* opcode/arc.h (NPS_CMEM_HIGH_VALUE): Define.

ld/ChangeLog:

	* testsuite/ld-arc/arc.exp: New file.
	* testsuite/ld-arc/nps-1.s: New file.
	* testsuite/ld-arc/nps-1a.d: New file.
	* testsuite/ld-arc/nps-1b.d: New file.
	* testsuite/ld-arc/nps-1b.err: New file.

opcodes/ChangeLog:

	* arc-nps400-tbl.h: Add xldb, xldw, xld, xstb, xstw, and xst
	instructions.
	* arc-opc.c (insert_nps_cmem_uimm16): New function.
	(extract_nps_cmem_uimm16): New function.
	(arc_operands): Add NPS_XLDST_UIMM16 operand.