nptl: mark symbols with libc forwarder hidden

[Austin Foxley]

On 04/14/2010 10:01 AM, Timo Teräs wrote:
> Add attribute_hidden to all symbols having libc forwarder. This prevents
> recursive self calls which would happen if libc is before libpthread in
> linking order: the forwarder functions would call itself via the function
> table, since the libpthread symbols would get overwritten with libc ones.
> This has not been a problem in glibc since there these symbols are marked
> hidden with linker version-script. Since we don't use one, we need to mark
> these explicitly.
> 
> Signed-off-by: Timo Teräs <timo.teras at iki.fi>

This looks like what we want. I'll apply this.

-Austin