[svn r112] Fixed 'case 1,2,3:' style case statements. Fixed a bunch of bugs with return/break/continue in loops. Fixed support for the DMDFE hidden implicit return value variable. This can be needed for some foreach statements where the loop body is converted to a nested delegate, but also possibly returns from the function. Added std.math to phobos. Added AA runtime support code, done ground work for implementing AAs. Several other bugfixes.

module union2;

pragma(LLVM_internal, "notypeinfo")
union U
{
    float f;
    long l;
}

U u;

void main()
{
    assert(u.f !<>= 0);
    {
        uint* p = 1 + cast(uint*)&u;
        {assert(*p == 0);}
    }
}