I forgot powerpc64 has its own gc_mark_dynamic_ref.
PR ld/17615
* elf64-ppc.c (ppc64_elf_gc_mark_dynamic_ref): Don't drop
ELF_COMMON_DEF syms.
+2015-01-20 Alan Modra <amodra@gmail.com>
+
+ PR ld/17615
+ * elf64-ppc.c (ppc64_elf_gc_mark_dynamic_ref): Don't drop
+ ELF_COMMON_DEF syms.
+
2015-01-19 Alan Modra <amodra@gmail.com>
PR ld/17615
if ((eh->elf.root.type == bfd_link_hash_defined
|| eh->elf.root.type == bfd_link_hash_defweak)
&& (eh->elf.ref_dynamic
- || (eh->elf.def_regular
+ || ((eh->elf.def_regular || ELF_COMMON_DEF_P (&eh->elf))
&& ELF_ST_VISIBILITY (eh->elf.other) != STV_INTERNAL
&& ELF_ST_VISIBILITY (eh->elf.other) != STV_HIDDEN
&& (!info->executable