* xcofflink.c (xcoff_mark_symbol_by_name): New function.
(bfd_xcoff_size_dynamic_sections): Use it to mark the entry,
init and fini functions. Do garbage collection for objects
without an entry point too.
ld/testsuite/
* ld-powerpc/aix-gc-1.s, ld-powerpc/aix-gc-1.ex,
ld-powerpc/aix-gc-1-32.dd, ld-powerpc/aix-gc-1-64.dd,
ld-powerpc/aix-weak-1-gcdso.dnd, ld-powerpc/aix-weak-1-gcdso.hd,
ld-powerpc/aix-weak-1-gcdso.nd: New tests.
* ld-powerpc/aix52.exp: Run them.
