Update comments now that LLVM PR3861 has been fixed. However, since conditionally removing the workaround makes the ABI dependent on LLVM version, I reconsidered that. (The same revision of LDC compiling for the same target should probably produce code that follows the same ABI, right?)

void main()
{
    int[4] a = [1,2,3,4];
    int[4] b = [5,6,7,8];
    a[] += b[] / 2;
    assert(a[0] == 3);
    assert(a[1] == 5);
    assert(a[2] == 6);
    assert(a[3] == 8);
}