[svn r261] Fixed debug info for integer and floating local variables, can now be inspected in GDB. Did a lot of smaller cleans up here and there. Replaced more llvm::Foo with LLFoo for common stuff. Split up tollvm.cpp.

module union1;

pragma(LLVM_internal, "notypeinfo")
union U
{
    float f;
    int i;
}

void main()
{
    float f = 2;
    U u = U(f);
    assert(u.i == *cast(int*)&f);
}