Enable regenerator in legacy bundles

.changeset/fresh-paws-argue.md

@@ -0,0 +1,5 @@
+---
+"preact-cli": patch
+---
+
+Transpile generators and async functions in legacy bundles. Async functions were inadvertently transpiled to generators in 3.3.0, this transpiles them to ES5.

packages/cli/lib/lib/babel-config.js

@@ -10,8 +10,7 @@ module.exports = function (env, options = {}) {
 					modules: options.modules || false,
 					targets: {
 						browsers: options.browsers,
-					},
-					exclude: ['transform-regenerator'],
+					}
 				},
 			],
 		],

packages/cli/lib/lib/webpack/webpack-base-config.js

@@ -86,6 +86,7 @@ module.exports = function createBaseConfig(env) {
 	const browserslistDefaults = ['> 0.25%', 'IE >= 9'];
 	const browserlistConfig = Object(browserslist.findConfig(cwd));
 	const browsers =
+	      	env.browserslist ||
 		(isProd ? browserlistConfig.production : browserlistConfig.development) ||
 		browserlistConfig.defaults ||
 		browserslistDefaults;