[PATCH] gold: Fix segfault on sparc with STT_SPARC_REGISTER and --gc-sections

[Cary Coutant]

> gold/
>  * symtab.cc (Symbol_table::add_from_relobj): Handle NULL symbols,
>  which will be present for STT_SPARC_REGISTER.
>  (Symbol_table::add_from_pluginobj): Likewise.
>  (Symbol_table::add_from_dynobj): Likewise.
>  (Symbol_table::add_from_incrobj): Removed dead code.

This is OK. I've committed it to master and backported it to the 2.27 branch.

Thanks!

-cary