Make Passerine 100% Wasm friendly

[slightknack]

I'm just going to keep a running list of things that sometimes break:

• Anything that relies on common::stamp.
• NaN tagging in closure captures, for whatever reason.

I need to add something along the lines of a wasm feature flag that replaces these dependencies - as for stamp, this can be removed and replaced with the hoisting step, we just need to do variable hoisting before macro expansion.