zig/BRANCH_TODO

Finish these thigns before merging teh branch

 * it gets the wrong answers with `-target-feature -sse,-avx`

 * finish refactoring target/arch/*
 * `zig builtin` integration 
 * move target details to better location
 * +foo,-bar vs foo,bar
 * baseline features


const riscv32_default_features: []*const std.target.Feature = &[_]*const std.target.Feature{
    &std.target.riscv.feature_a,
    &std.target.riscv.feature_c,
    &std.target.riscv.feature_d,
    &std.target.riscv.feature_f,
    &std.target.riscv.feature_m,
    &std.target.riscv.feature_relax,
};

const riscv64_default_features: []*const std.target.Feature = &[_]*const std.target.Feature{
    &std.target.riscv.feature_bit64,
    &std.target.riscv.feature_a,
    &std.target.riscv.feature_c,
    &std.target.riscv.feature_d,
    &std.target.riscv.feature_f,
    &std.target.riscv.feature_m,
    &std.target.riscv.feature_relax,
};

// Same as above but without sse.
const i386_default_features_freestanding: []*const std.target.Feature = &[_]*const std.target.Feature{
    &std.target.x86.feature_cmov,
    &std.target.x86.feature_cx8,
    &std.target.x86.feature_fxsr,
    &std.target.x86.feature_mmx,
    &std.target.x86.feature_nopl,
    &std.target.x86.feature_slowUnalignedMem16,
    &std.target.x86.feature_x87,
};