Remove an old workaround that was kept around for ABI-compatibility on x86-64 between different LLVM versions. This means LLVM r67588 is required if you want to compile for x86-64, otherwise the backend will assert when you try to return e.g. struct { int i; char c; } from a function. (In particular, this is no longer compatible with LLVM 2.5) It also means that any code returning small structs on x86-64 will probably need to be recompiled in order to be linkable to code compiled with this change.

module arrays5;
void main()
{
    auto arr = new float[5];
    {arr[4] = 1f;}
    {assert(arr[0] !<>= 0f);}
    {assert(arr[1] !<>= 0f);}
    {assert(arr[2] !<>= 0f);}
    {assert(arr[3] !<>= 0f);}
    {assert(arr[4] == 1f);}
}