use custom es6 modularization instead of MODULARIZE=1

glslang/OSDependent/Web/glslang.after.js

@@ -0,0 +1,26 @@
+export default (() => {
+    const initialize = () => {
+        return new Promise(resolve => {
+            Module({
+                locateFile() {
+                    const i = import.meta.url.lastIndexOf('/')
+                    return import.meta.url.substring(0, i) + '/glslang.wasm';
+                },
+                onRuntimeInitialized() {
+                    resolve({
+                        compileGLSLZeroCopy: this.compileGLSLZeroCopy,
+                        compileGLSL: this.compileGLSL,
+                    });
+                },
+            });
+        });
+    };
+
+    let instance;
+    return () => {
+        if (!instance) {
+            instance = initialize();
+        }
+        return instance;
+    };
+})();