* For the next issue, first some background: unlike GNU as, which can
declare COMDAT group sections in one go like this
.section .text.foo,"axG",@progbits,foo,comdat
and defines the signature symbol itself as needed, Sun as needs
separate declarations of the group and section as well as a definition
of the group signature symbol
** The C++ frontend generates an artificial identifier as group
signature in cp/optimize.c (cdtor_comdat_group), which isn't ever
defined (and doesn't demangle at all). To solve that problem, I've
decided to set a flag on that identifier which config/sol2.c
(solaris_elf_asm_comdat_section) can use to decide if it needs to
define the symbol. I've chosen IDENTIFIER_CTOR_OR_DTOR_P since it
seemed to make most sense and the obvious DECL_ARTIFICIAL cannot be
set on an IDENTIFIER_NODE. The complication is that I cannot simply
include cp/cp-tree.h in sol2.c since all non-C++ compilers fail to
link. So I've cheated and use the underlying TREE_LANG_FLAG_3
instead. This is clearly a hack, but worked for me.