* elf32-arm.c (elf32_arm_final_link_relocate): Use origin of output
segment containing the relocating symbol instead of assuming 0 for
sb group relocations.
* ld-arm/group-relocs-ldr-bad.s: Redefine bar into foo section
beyond 16 bit offset width.
* ld-arm/group-relocs-ldrs-bad.s: Likewise.
* ld-arm/group-relocs-ldr-bad.d: Adjust expected result.
* ld-arm/group-relocs-ldrs-bad.d: Likewise.
* ld-arm/group-relocs.s: Add comments. Move symbols used for sb
group relocations into .data section. Drop section zero. Use pc/r0
as base register when pc/sb group relocations are used.
* ld-arm/group-relocs.d: Adjust expected result.
* ld-arm/group-relocs-alu-bad-2.d: New test for sb group relocation.
* ld-arm/group-relocs-ldc-bad-2.d: Likewise.
* ld-arm/group-relocs-ldr-bad-2.d: New test for pc group relocation.
* ld-arm/group-relocs-ldrs-bad-2.d: Likewise.
* ld-arm/unresolved-2.d: Add sb relocation failure test.
* ld-arm/group-relocs-alu-bad-2.s: New test source.
* ld-arm/group-relocs-ldr-bad-2.s: Likewise.
* ld-arm/group-relocs-ldrs-bad-2.s: Likewise.
* ld-arm/group-relocs-ldc-bad-2.s: Likewise.
* ld-arm/unresolved-2.s: Likewise.
* ld-arm/arm-elf.exp: For group-relocs, drop section zero start
definition. Run the new tests.
