[CMake] statically linking libstdc++ problem.

[christopher at baus.net]

> 2.) Create a directory that contains a symlink to the static version of
> the library and then use the LINK_DIRECTORIES command to add it to the
> link path.  Then the linker will find the static version and use it.

I got this working except I need to pass -static-libgcc to the linker. 
How should I do that?  I hacked the makefile by hand, to get a static
libgcc.