LLVM: Dynamic Library Support

dynamic library status:

 * Supported: Linux 64bit, Mac OSX 64bit
 * Unsupported: Linux 32bit, Mac OSX 32bit, Windows 32bit

The LLVM backend doesn't support dynamic libraries at the moment.

LLC supports a flag called '-relocation-mode' that can be used to support this, it takes the following options:

default        - let the target choose.
static         - static code.
pic            - PIC code.
dynamic-no-pic - Dynamic references but static code

This roughly corresponds to GHC -fPIC, and -dynamic flags.

Linux: Simply adding the correct flag to LLC seems to work fine. Mac OSX, Windows: Adding the correct flag doesn't work at all, all programs segfault.