[LD][AARCH64]Add group relocations to create PC-relative offset.

[LD][AARCH64]Add group relocations to create PC-relative offset.

This is a patch to add linker support for group relocations to create a
16, 32, 48, or 64 bit PC-relative offset inline.

The following relocations are added along with the test cases:
BFD_RELOC_AARCH64_MOVW_PREL_G0, BFD_RELOC_AARCH64_MOVW_PREL_G0_NC,
BFD_RELOC_AARCH64_MOVW_PREL_G1, BFD_RELOC_AARCH64_MOVW_PREL_G1_NC,
BFD_RELOC_AARCH64_MOVW_PREL_G2, BFD_RELOC_AARCH64_MOVW_PREL_G2_NC,
BFD_RELOC_AARCH64_MOVW_PREL_G3.

bfd/

2018-01-24  Renlin Li  <renlin.li@arm.com>

	* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Add support for
	BFD_RELOC_AARCH64_MOVW_PREL_G0, BFD_RELOC_AARCH64_MOVW_PREL_G0_NC,
	BFD_RELOC_AARCH64_MOVW_PREL_G1, BFD_RELOC_AARCH64_MOVW_PREL_G1_NC,
	BFD_RELOC_AARCH64_MOVW_PREL_G2, BFD_RELOC_AARCH64_MOVW_PREL_G2_NC,
	BFD_RELOC_AARCH64_MOVW_PREL_G3.
	* elfxx-aarch64.c (_bfd_aarch64_elf_put_addend): Likewise.
	(_bfd_aarch64_elf_resolve_relocation): Likewise.

ld/

2018-01-24  Renlin Li  <renlin.li@arm.com>

	* testsuite/ld-aarch64/aarch64-elf.exp: Run new testes.
	* testsuite/ld-aarch64/emit-relocs-287.s: Fix test case.
	* testsuite/ld-aarch64/emit-relocs-287.d: Fix expected output.
	* testsuite/ld-aarch64/emit-relocs-287-overflow.s: New.
	* testsuite/ld-aarch64/emit-relocs-287-overflow.d: New.
	* testsuite/ld-aarch64/emit-relocs-288.d: New.
	* testsuite/ld-aarch64/emit-relocs-288.s: New.
	* testsuite/ld-aarch64/emit-relocs-289.d: New.
	* testsuite/ld-aarch64/emit-relocs-289.s: New.
	* testsuite/ld-aarch64/emit-relocs-289-overflow.s: New.
	* testsuite/ld-aarch64/emit-relocs-289-overflow.d: New.
	* testsuite/ld-aarch64/emit-relocs-290.d: New.
	* testsuite/ld-aarch64/emit-relocs-290.s: New.
	* testsuite/ld-aarch64/emit-relocs-291.d: New.
	* testsuite/ld-aarch64/emit-relocs-291.s: New.
	* testsuite/ld-aarch64/emit-relocs-291-overflow.s: New.
	* testsuite/ld-aarch64/emit-relocs-291-overflow.d: New.
	* testsuite/ld-aarch64/emit-relocs-292.d: New.
	* testsuite/ld-aarch64/emit-relocs-292.s: New.
	* testsuite/ld-aarch64/emit-relocs-293.d: New.
	* testsuite/ld-aarch64/emit-relocs-293.s: New.