dynamic libraries not runtime loadable on linux after all? confused by lack of Posix implementation of rt_loadLibrary in dmain2.d

[J]

I thought that runtime loading of dynamic libraries was 
implemented on Linux. But the code says otherwise.

I'm looking at the master branch of 
https://github.com/D-Programming-Language/druntime.git

When I look at druntime/src/rt/dmain2.d, commit 
45a0838a7108850a20da3be5850976024d91f5ed from July 15 2013, the 
following appears:

extern (C) void* rt_loadLibrary(in char[] name)
{
     version (Windows)
     {
       // ... omit windows implementation

     else version (Posix)
     {
         throw new Exception("rt_loadLibrary not yet implemented 
on Posix.");
     }
}

Is the implementation hiding on a different branch perhaps?  Why 
were folks saying it was done?

Thanks.

J