remove passing AST, redecode AST in Generator

lib/wasm/WebAssemblyGenerator.js

@@ -6,9 +6,9 @@
 
 const Generator = require("../Generator");
 const { RawSource } = require("webpack-sources");
-const WebAssemblyParser = require("./WebAssemblyParser");
 
 const { editWithAST, addWithAST } = require("@webassemblyjs/wasm-edit");
+const { decode } = require("@webassemblyjs/wasm-parser");
 const t = require("@webassemblyjs/ast");
 
 function compose(...fns) {
@@ -244,9 +244,13 @@ const addInitFunction = ({
 
 class WebAssemblyGenerator extends Generator {
 	generate(module) {
-		const ast = WebAssemblyParser.getAst(module);
 		const bin = module.originalSource().source();
 
+		const ast = decode(bin, {
+			ignoreDataSection: true,
+			ignoreCodeSection: true
+		});
+
 		const importedGlobals = getImportedGlobals(ast);
 		const countImportedFunc = getCountImportedFunc(ast);
 		const startAtFuncIndex = getStartFuncIndex(ast);

lib/wasm/WebAssemblyParser.js

@@ -29,30 +29,20 @@ const decoderOpts = {
 	ignoreDataSection: true
 };
 
-/** @type {WeakMap<Module, TODO>} */
-const astStore = new WeakMap();
-
 class WebAssemblyParser extends Tapable {
 	constructor(options) {
 		super();
 		this.hooks = {};
 		this.options = options;
 	}
 
-	static getAst(module) {
-		return astStore.get(module);
-	}
-
 	parse(binary, state) {
 		// flag it as ESM
 		state.module.buildMeta.exportsType = "namespace";
 
 		// parse it
 		const ast = decode(binary, decoderOpts);
 
-		// cache it to be available for generators
-		astStore.set(state.module, ast);
-
 		// extract imports and exports
 		const exports = (state.module.buildMeta.providedExports = []);
 		t.traverse(ast, {