Now that we're using LLVM 2.5, we can stop always running the CFGSimplification pass. The pass was originally added as a workaround for a LLVM 2.4 bug where debug info would reference labels that have been optimized away.

module neg;

void main()
{
    int i = 32;
    long l = 55;
    float f = 23;
    double d = 4;
    assert(-i == -32);
    assert(-l == -55);
    assert(-f == -23);
    assert(-d == -4);
}