Changed the handling of variadic intrinsics a bit. Removed the -fp80 option and made real be 80bit floats on X86, this is what the D spec really says it should be and fixes a bunch of issues. Changed the handling of parameter attributes to a bit more generalized approach. Added sext/zext attributes for byte/short/ubyte/ushort parameters, fixes #60 . Parameter attribs now properly set for intrinsic calls if necessary. Made the tango.math.Math patch less intrusive. Fixed/added some mini tests.

module c;

void main()
{
    ushort a = 0xFFF0;
    ushort b = 0x0FFF;
    auto t = a & b;
    a &= b;
    assert(t == a);
}