Compile dart2wasm modules using the JS runtime exported compileStreaming (#51488)

With [1] dart2wasm started using the new Wasm built-in string import
`wasm:js-string`.

With [2] dart2wasm started exporting `compile` and `compileStreaming`
from the generated JS runtime to compile dart2wasm-generated modules
with the `wasm:js-string` built-in, polyfilling it when not available.

Update Wasm compilation code in Flutter to use `compileStreaming` from
the JS runtime, enabling fast `jwasm:js-string` module when available.

[1]: dart-lang/sdk@44c2e17
[2]: dart-lang/sdk@4cd6096

Author: osa1

lib/web_ui/flutter_js/src/entrypoint_loader.js

@@ -152,11 +152,11 @@ export class FlutterEntrypointLoader {
       let jsSupportRuntimeUri = resolveUrlWithSegments(entrypointBaseUrl, jsSupportRuntimePath);
       if (this._ttPolicy != null) {
         jsSupportRuntimeUri = this._ttPolicy.createScriptURL(jsSupportRuntimeUri);
-      }  
-      const dartModulePromise = WebAssembly.compileStreaming(fetch(moduleUri));
-
+      }
       const jsSupportRuntime = await import(jsSupportRuntimeUri);
 
+      const dartModulePromise = jsSupportRuntime.compileStreaming(fetch(moduleUri));
+
       let imports;
       if (build.renderer === "skwasm") {
         imports = (async () => {