Fix the problems exposed by the callingconv1.d test case. The first was that unless otherwise specified, inputs are assumed to be in registers even if they specify a "matching output" that's in memory. While testing that fix, I also ran into a bug causing the generated "matching output" for any input was always the first one instead of the correct one.

// ifloat

module typeinfo1.ti_ifloat;

private import typeinfo1.ti_float;

class TypeInfo_o : TypeInfo_f
{
    char[] toString() { return "ifloat"; }
}