fix(build): use builder pattern when creating unicode escape sequence…

…s to solve problems in legacy browsers

src/build/build.ts

@@ -6,11 +6,12 @@ import {BROTLI_OPTIONS} from "./options/brotli-options";
 import {ZLIB_OPTIONS} from "./options/zlib-options";
 import {IPolyfillFeature} from "../polyfill/i-polyfill-feature";
 import {build as esbuild} from "esbuild";
-import {transform} from "@swc/core";
 import {tmpdir} from "os";
 import {join} from "path";
 import {generateRandomHash} from "../util/hash-util/hash-util";
 import {unlinkSync, writeFileSync} from "fs";
+import {transform} from "@swc/core";
+import {UnicodeEscapeRestorer} from "./swc/unicode-escape-restorer";
 
 function stringifyPolyfillFeature(feature: IPolyfillFeature): string {
 	const metaEntries = Object.entries(feature.meta);
@@ -90,7 +91,9 @@ export async function build({paths, features, featuresRequested, userAgent, cont
 				filename: virtualOutputFileName,
 				jsc: {
 					target: ecmaVersion
-				}
+				},
+				// replace unicode characters with a builder pattern to fix issues in legacy browsers
+				plugin: m => new UnicodeEscapeRestorer().visitProgram(m)
 			}));
 		}