Support the new name mangling scheme for components

This commit adds support for WebAssembly/component-model#378 to
`wit-component`. Notably a new set of alternative names are registered
and recognized during the module-to-component translation process.
Support for the previous set of names are all preserved and will
continue to be supported for some time. The new names are, for now,
recognized in parallel to the old names.

This involved some refactoring to the validation part of `wit-component`
and further encapsulation of various names to one small location instead
of a shared location for everywhere else to use as well.

Author: alexcrichton

crates/wit-component/src/dummy.rs

@@ -67,7 +67,7 @@ pub fn dummy_module(resolve: &Resolve, world: WorldId) -> Vec<u8> {
             WorldItem::Interface { id: export, .. } => {
                 let name = resolve.name_world_key(name);
                 for (_, func) in resolve.interfaces[*export].functions.iter() {
-                    let name = func.core_export_name(Some(&name));
+                    let name = func.legacy_core_export_name(Some(&name));
                     push_func(&mut wat, &name, resolve, func);
                 }
 

crates/wit-component/src/encoding.rs

@@ -72,7 +72,7 @@
 //! component model.
 
 use crate::metadata::{self, Bindgen, ModuleMetadata};
-use crate::validation::{Export, ExportMap, Import, ImportInstance, ImportMap, RESOURCE_DROP};
+use crate::validation::{Export, ExportMap, Import, ImportInstance, ImportMap};
 use crate::StringEncoding;
 use anyhow::{anyhow, bail, Context, Result};
 use indexmap::{IndexMap, IndexSet};
@@ -647,6 +647,7 @@ impl<'a> EncodingState<'a> {
         }
 
         let world = &resolve.worlds[self.info.encoder.metadata.world];
+
         for export_name in exports {
             let export_string = resolve.name_world_key(export_name);
             match &world.exports[export_name] {
@@ -1457,7 +1458,7 @@ impl<'a> EncodingState<'a> {
             Import::ImportedResourceDrop(key, iface, id) => {
                 let ty = &resolve.types[*id];
                 let name = ty.name.as_ref().unwrap();
-                name_tmp = format!("{RESOURCE_DROP}{name}");
+                name_tmp = format!("{name}_drop");
                 (key, &name_tmp, iface.map(|_| resolve.name_world_key(key)))
             }
             Import::WorldFunc(key, name) => (key, name, None),

crates/wit-component/src/encoding/world.rs

@@ -1,6 +1,6 @@
 use super::{Adapter, ComponentEncoder, LibraryInfo, RequiredOptions};
 use crate::validation::{
-    validate_adapter_module, validate_module, Import, ImportMap, ValidatedModule, RESOURCE_DROP,
+    validate_adapter_module, validate_module, Import, ImportMap, ValidatedModule,
 };
 use anyhow::{Context, Result};
 use indexmap::{IndexMap, IndexSet};
@@ -461,7 +461,7 @@ impl ImportedInterface {
         let name = ty.name.as_deref().expect("resources must be named");
 
         if required.resource_drops.contains(&id) {
-            let name = format!("{RESOURCE_DROP}{name}");
+            let name = format!("{name}_drop");
             let prev = self.lowerings.insert(name, Lowering::ResourceDrop(id));
             assert!(prev.is_none());
         }