tests: fix path match on Windows

Author: haoqunjiang

packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js

@@ -32,7 +32,7 @@ test('polyfill detection', () => {
   // promise polyfill alone doesn't work in IE, needs this as well. fix: #1642
   expect(code).toMatch(`import "core-js/modules/es6.array.iterator"`)
   // usage-based detection
-  expect(code).toMatch(/import _Map from ".*@babel\/runtime-corejs2\/core-js\/map"/)
+  expect(code).toMatch(/import _Map from ".*runtime-corejs2\/core-js\/map"/)
 })
 
 test('modern mode always skips polyfills', () => {
@@ -49,7 +49,7 @@ test('modern mode always skips polyfills', () => {
   // default includes
   expect(code).not.toMatch(`import "core-js/modules/es6.promise"`)
   // usage-based detection
-  expect(code).not.toMatch(/import _Map from ".*@babel\/runtime-corejs2\/core-js\/map"/)
+  expect(code).not.toMatch(/import _Map from ".*runtime-corejs2\/core-js\/map"/)
 
   ;({ code } = babel.transformSync(`
     const a = new Map()
@@ -63,7 +63,7 @@ test('modern mode always skips polyfills', () => {
   // default includes
   expect(code).not.toMatch(`import "core-js/modules/es6.promise"`)
   // usage-based detection
-  expect(code).not.toMatch(/import _Map from ".*@babel\/runtime-corejs2\/core-js\/map"/)
+  expect(code).not.toMatch(/import _Map from ".*runtime-corejs2\/core-js\/map"/)
   delete process.env.VUE_CLI_MODERN_BUILD
 })
 
@@ -92,7 +92,7 @@ test('async/await', () => {
   // should use regenerator runtime
   expect(code).toMatch(`import "regenerator-runtime/runtime"`)
   // should use required helper instead of inline
-  expect(code).toMatch(/import _asyncToGenerator from ".*@babel\/runtime-corejs2\/helpers\/esm\/asyncToGenerator\"/)
+  expect(code).toMatch(/import _asyncToGenerator from ".*runtime-corejs2\/helpers\/esm\/asyncToGenerator\"/)
 })
 
 test('jsx', () => {