feat(import-bundle): Thread native flag

Author: kriskowal

packages/import-bundle/NEWS.md

@@ -1,5 +1,16 @@
 User-visible changes to `@endo/import-bundle`:
 
+# Next release
+
+Experimental:
+
+- Adds a `__native__: true` option that indicates that the application will
+  fall through to the native implementation of Compartment, currently only
+  available on XS, which lacks support for precompiled module sources (as exist
+  in many archived applications, particularly Agoric smart contract bundles)
+  and instead supports loading modules from original sources (which is not
+  possible at runtime on XS).
+
 # v1.3.0 (2024-10-10)
 
 - Adds support for `endoScript` format bundles.

packages/import-bundle/src/index.js

@@ -24,6 +24,7 @@ export async function importBundle(bundle, options = {}, powers = {}) {
     transforms = [],
     inescapableTransforms = [],
     inescapableGlobalProperties = {},
+    __native__ = false,
     expectedSha512 = undefined,
   } = options;
   const {
@@ -71,6 +72,7 @@ export async function importBundle(bundle, options = {}, powers = {}) {
     const { namespace } = await archive['import']({
       globals: endowments,
       __shimTransforms__: transforms,
+      __native__,
       // @ts-expect-error TS2740 missing properties from type
       Compartment: CompartmentToUse,
     });