Huc6820 platform bugs

[est77]

Wrong opcode for jmp (addr, X). See https://github.com/wiz-lang/wiz/issues/138.

Branch on bit (branch on bit - goto label if zp $ n) only works for n == 6 and 7. Other bit indices error with: error: bit indexing $ operator is not allowed in conditional.

Using the tst intrinsic directly or indirectly produces a series of internal error messages and crashes wiz with a fatal: address was supposed to be reserved here, by code.

[Bananattack]

The issues with tst should be resolved now:

bank prg @ 0x8000 : [constdata; 0x8000];
bank zeropage @ 0x2000 : [vardata; 0x100];
bank ram @ 0x2200 : [vardata; 0x600];

in zeropage {
    var zp_b0, zp_b1, zp_b2, zp_b3, zp_b4, zp_b5, zp_b6, zp_b7 : u8;
    var zp_array : [u8; 16];
}

in ram {
    var ram_b0, ram_b1, ram_b2, ram_b3, ram_b4, ram_b5, ram_b6, ram_b7 : u8;
    var ram_array : [u8; 16];
}

in prg {
    tst(0, zp_b0);
    tst(0, zp_array[x]);
    tst(0, ram_b0);
    tst(0, ram_array[x]);
    if zp_b0 & 0x40 != 0 { 
        // ...
    }
}

I also added a support for a tstbit(mem, n) intstrinsic which takes a bit index from 0 .. 7 and mem being either zero page, zero page indexed by x, absolute or absolute indexed by x, but otherwise works similar to tst. When generating if statements that involve bit indexing, wiz will automatically call tstbit:

tstbit(zp_b0, 2);
if zp_b0 $ 4 {
    // ...
}

[est77]

Thanks for the fixes!