This isn't exactly bootstrapping a compiler. The concept there is that in the end you do not need the foreign compiler. In this case, you still need the native

This isn't exactly bootstrapping a compiler. The concept there is that in the end you do not need the foreign compiler. In this case, you still need the native implementation to run the php implementation, giving it much less practicle purpose than bootsrapping compiled languages. From a theoratical perspective, this is equivelent to bootstrapping, as it is not an intrinsic property of PHP that it does not get compiled.