Disabling all optimizations isn't even enough- fundamentally what you need is a much narrower specification for how the source language maps to its output. Even -O0 doesn't give you that, and in fact will often be counterproductive (e.g. you'll get branches in places that the optimizer would have removed them).
The problem with this is that no general purpose compiler wants to tie its own hands behind its back in this way, for the benefit of one narrow use case. It's not just that it would cost performance for everyone else, but also that it requires a totally different approach to specification and backwards compatibility, not to mention deep changes to compiler architecture.
You almost may as well just design a new language, at that point.
The problem with this is that no general purpose compiler wants to tie its own hands behind its back in this way, for the benefit of one narrow use case. It's not just that it would cost performance for everyone else, but also that it requires a totally different approach to specification and backwards compatibility, not to mention deep changes to compiler architecture.
You almost may as well just design a new language, at that point.