Ghost Kernel

With the latest commits, C++ runtime features (most notably exceptions) and thread-local storage are now supported in executables and shared libraries.

The toolchain build was modified so that the shared version of libgcc libgcc_s.so.1 is now built. Using -shared-libgcc as a linker flag will now cause libgcc to be linked dynamically and therefore allow exception handling over multiple shared objects.

I've adapted the test suite to now call a runtime test program that performs multiple tests for global constructors, exception handling and TLS.

With those additions, shared library support should now be sufficient to continue work on other parts, most notably inter-process messaging will next be implemented in the new kernel implementation.