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 interface3;

extern(C) int printf(char*,...);

interface I
{
    void func();
}

class C : I
{
    int i = 42;
    override void func()
    {
        printf("hello %d\n", i);
        i++;
    }
}

void main()
{
    scope c = new C;
    {c.func();}
    {
        I i = c;
        {i.func();}
    }
    {printf("final %d\n", c.i);}
    {assert(c.i == 44);}
}