Refactor snapshot build (#2825)

Instead of using core/snapshot_creator.rs, instead two crates are
introduced which allow building the snapshot during build.rs.

Rollup is removed and replaced with our own bundler. This removes
the Node build dependency. Modules in //js now use Deno-style imports
with file extensions, rather than Node style extensionless imports.

This improves incremental build time when changes are made to //js files
by about 40 seconds.

1 files changed, 4 insertions, 4 deletions

diff --git a/js/files.ts b/js/files.ts
index 0335056b3..98d18f0cf 100644
--- a/js/files.ts
+++ b/js/files.ts
@@ -9,13 +9,13 @@ import {
   SyncReader,
   SyncWriter,
   SyncSeeker
-} from "./io";
-import { sendAsyncMinimal, sendSyncMinimal } from "./dispatch_minimal";
-import * as dispatch from "./dispatch";
+} from "./io.ts";
+import { sendAsyncMinimal, sendSyncMinimal } from "./dispatch_minimal.ts";
+import * as dispatch from "./dispatch.ts";
 import {
   sendSync as sendSyncJson,
   sendAsync as sendAsyncJson
-} from "./dispatch_json";
+} from "./dispatch_json.ts";
 
 /** Open a file and return an instance of the `File` object
  *  synchronously.