fix: js compatibility

Author: alpha0010

src/__tests__/util.test.ts

@@ -33,6 +33,7 @@ it('extracts dirname', () => {
   expect(Util.dirname('abc$$def$', '$')).toBe('abc');
 
   expect(Util.dirname('abc::def:', '::')).toBe('abc');
+  expect(Util.dirname('abc$`$`def$`$`hij$`klm', '$`')).toBe('abc$`def$`hij');
 });
 
 it('extracts extname', () => {

src/util.ts

@@ -10,7 +10,7 @@ function regexEscape(literal: string) {
  */
 function normalizeSeparator(path: string, separator: string) {
   const sepRe = new RegExp(`(${regexEscape(separator)}){2,}`, 'g');
-  return path.replace(sepRe, separator.replaceAll('$', '$$$$'));
+  return path.replace(sepRe, separator.replace(/\$/g, '$$$$'));
 }
 
 /**