fix(wasm): support inlined WASM in Node < v16 (fix #8620) (#8622)

Author: pastelmind

packages/vite/src/node/plugins/wasm.ts

@@ -7,11 +7,21 @@ const wasmHelperId = '/__vite-wasm-helper'
 const wasmHelper = async (opts = {}, url: string) => {
   let result
   if (url.startsWith('data:')) {
-    // @ts-ignore
-    const binaryString = atob(url.replace(/^data:.*?base64,/, ''))
-    const bytes = new Uint8Array(binaryString.length)
-    for (let i = 0; i < binaryString.length; i++) {
-      bytes[i] = binaryString.charCodeAt(i)
+    const urlContent = url.replace(/^data:.*?base64,/, '')
+    let bytes
+    if (typeof Buffer === 'function' && typeof Buffer.from === 'function') {
+      bytes = Buffer.from(urlContent, 'base64')
+    } else if (typeof atob === 'function') {
+      // @ts-ignore
+      const binaryString = atob(urlContent)
+      bytes = new Uint8Array(binaryString.length)
+      for (let i = 0; i < binaryString.length; i++) {
+        bytes[i] = binaryString.charCodeAt(i)
+      }
+    } else {
+      throw new Error(
+        'Failed to decode base64-encoded data URL, Buffer and atob are not supported'
+      )
     }
     // @ts-ignore
     result = await WebAssembly.instantiate(bytes, opts)