refactor(web): use encoding_rs for text encoding (#10844)

This commit removes all JS based text encoding / text decoding. Instead
encoding now happens in Rust via encoding_rs (already in tree). This
implementation retains stream support, but adds the last missing
encodings. We are incredibly close to 100% WPT on text encoding now.

This should reduce our baseline heap by quite a bit.

1 files changed, 12 insertions, 4 deletions

diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index d64625993..7ec422c1f 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -16,6 +16,8 @@ delete Object.prototype.__proto__;
   const errorStack = window.__bootstrap.errorStack;
   const os = window.__bootstrap.os;
   const timers = window.__bootstrap.timers;
+  const base64 = window.__bootstrap.base64;
+  const encoding = window.__bootstrap.encoding;
   const Console = window.__bootstrap.console.Console;
   const worker = window.__bootstrap.worker;
   const signals = window.__bootstrap.signals;
@@ -198,6 +200,12 @@ delete Object.prototype.__proto__;
         return new DOMException(msg, "NotSupported");
       },
     );
+    core.registerErrorBuilder(
+      "DOMExceptionInvalidCharacterError",
+      function DOMExceptionInvalidCharacterError(msg) {
+        return new DOMException(msg, "InvalidCharacterError");
+      },
+    );
   }
 
   class Navigator {
@@ -277,8 +285,8 @@ delete Object.prototype.__proto__;
     ),
     Request: util.nonEnumerable(fetch.Request),
     Response: util.nonEnumerable(fetch.Response),
-    TextDecoder: util.nonEnumerable(TextDecoder),
-    TextEncoder: util.nonEnumerable(TextEncoder),
+    TextDecoder: util.nonEnumerable(encoding.TextDecoder),
+    TextEncoder: util.nonEnumerable(encoding.TextEncoder),
     TransformStream: util.nonEnumerable(streams.TransformStream),
     URL: util.nonEnumerable(url.URL),
     URLSearchParams: util.nonEnumerable(url.URLSearchParams),
@@ -295,8 +303,8 @@ delete Object.prototype.__proto__;
     TransformStreamDefaultController: util.nonEnumerable(
       streams.TransformStreamDefaultController,
     ),
-    atob: util.writable(atob),
-    btoa: util.writable(btoa),
+    atob: util.writable(base64.atob),
+    btoa: util.writable(base64.btoa),
     clearInterval: util.writable(timers.clearInterval),
     clearTimeout: util.writable(timers.clearTimeout),
     console: util.writable(