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.

module typeinfos2;

import
typeinfo2.ti_AC,
typeinfo2.ti_Adouble,
typeinfo2.ti_Afloat,
typeinfo2.ti_Ag,
typeinfo2.ti_Aint,
typeinfo2.ti_Along,
typeinfo2.ti_Areal,
typeinfo2.ti_Ashort,
typeinfo2.ti_C;