Fix EXPORT_ES6 + locateFile

`Module['locateFile']` needs to be checked even in `EXPORT_ES6` mode.

In #14135 I did this for `new Worker`, but not for Wasm binary locator, so it broke existing usages of EXPORT_ES6 + custom `locateFile` function.

src/preamble.js

@@ -747,13 +747,17 @@ function instrumentWasmTableWithAbort() {
 #endif
 
 #if EXPORT_ES6
-// Use bundler-friendly `new URL(..., import.meta.url)` pattern; works in browsers too.
-var wasmBinaryFile = new URL('{{{ WASM_BINARY_FILE }}}', import.meta.url).toString();
-#else
+if (Module['locateFile']) {
+#endif
 var wasmBinaryFile = '{{{ WASM_BINARY_FILE }}}';
 if (!isDataURI(wasmBinaryFile)) {
   wasmBinaryFile = locateFile(wasmBinaryFile);
 }
+#if EXPORT_ES6
+} else {
+// Use bundler-friendly `new URL(..., import.meta.url)` pattern; works in browsers too.
+var wasmBinaryFile = new URL('{{{ WASM_BINARY_FILE }}}', import.meta.url).toString();
+}
 #endif
 
 function getBinary(file) {