[patch] First step to fix pr11866 during LTO

[Rafael Espíndola]

On 5 September 2013 16:04, Nick Kledzik <kledzik at apple.com> wrote:
> Rafael,
>
> When would the linker call this new lto_codegen_add_symtab_symbol() function?  What is the semantic difference between it and lto_codegen_add_must_preserve_symbol()?

The difference is the same as the two lists in the internalize level
that bill asked about (see
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130902/186896.html,
I will include something like that in the comments.).

In the plugin interface exposed by gold this corresponds to
PREVAILING_DEF_IRONLY_EXP (the api is documented in
http://gcc.gnu.org/wiki/whopr/driver).

Cheers,
Rafael