Separate out rust parsing step to support references to values stored in the parsed state.

src/wasm/macros.rs

@@ -3,11 +3,11 @@
 /// This exists to make changing the type signature easier.
 macro_rules! to_wasm {
     ($ostruct:ty, $istruct:ty, $original:ident, $wasm_context:ident, $standard_properties:ident, $fnbody:tt) => {
-        impl<'s, 'p> ToWasm for $istruct {
+        impl<'s, 'p> ToWasm<'p> for $istruct {
             type Output = $ostruct;
 
             fn to_wasm(
-                &self,
+                &'p self,
                 $wasm_context: crate::wasm::to_wasm::ToWasmContext<'_>,
             ) -> Result<Self::Output, crate::error::CustomError> {
                 let $original = self;