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.

4 files changed, 17 insertions, 13 deletions

diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index 5660b291c..c917a2880 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -38,8 +38,6 @@
     return core.opAsync("op_host_get_message", id);
   }
 
-  const decoder = new TextDecoder();
-
   /**
    * @param {string} permission
    * @return {boolean}
@@ -166,7 +164,7 @@
 
       this.#name = name;
       const hasSourceCode = false;
-      const sourceCode = decoder.decode(new Uint8Array());
+      const sourceCode = core.decode(new Uint8Array());
 
       if (
         specifier.startsWith("./") || specifier.startsWith("../") ||
diff --git a/runtime/js/40_read_file.js b/runtime/js/40_read_file.js
index 1efd5338d..7eee28d89 100644
--- a/runtime/js/40_read_file.js
+++ b/runtime/js/40_read_file.js
@@ -2,6 +2,7 @@
 "use strict";
 
 ((window) => {
+  const core = window.Deno.core;
   const { open, openSync } = window.__bootstrap.files;
   const { readAll, readAllSync } = window.__bootstrap.io;
 
@@ -29,8 +30,7 @@
     const file = openSync(path);
     try {
       const contents = readAllSync(file);
-      const decoder = new TextDecoder();
-      return decoder.decode(contents);
+      return core.decode(contents);
     } finally {
       file.close();
     }
@@ -40,8 +40,7 @@
     const file = await open(path);
     try {
       const contents = await readAll(file);
-      const decoder = new TextDecoder();
-      return decoder.decode(contents);
+      return core.decode(contents);
     } finally {
       file.close();
     }
diff --git a/runtime/js/41_prompt.js b/runtime/js/41_prompt.js
index d74a937aa..cb088dafa 100644
--- a/runtime/js/41_prompt.js
+++ b/runtime/js/41_prompt.js
@@ -5,7 +5,6 @@
   const { isatty } = window.__bootstrap.tty;
   const LF = "\n".charCodeAt(0);
   const CR = "\r".charCodeAt(0);
-  const decoder = new TextDecoder();
   const core = window.Deno.core;
 
   function alert(message = "Alert") {
@@ -70,7 +69,7 @@
       }
       buf.push(c[0]);
     }
-    return decoder.decode(new Uint8Array(buf));
+    return core.decode(new Uint8Array(buf));
   }
 
   window.__bootstrap.prompt = {
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(