${project.basedir} in pom.xml interpreted wrongly to a wrong absolute path in Windows 10.

Environment

• Operating System: Windows 10
• JDK version: 14
• Visual Studio Code version: 1.63.2
• Java extension version: 0.20.0 (Extension pack)

Steps To Reproduce

1. Set sourceDirectory in pom.xml to ${project.basedir}
2. Update project and use the command palette to open Java: Configure Classpath.
3. See the result.
4. Change ${project.basedir} to ${project.basedir}/src or anyone else. Repeat the steps above and see result.
   [Sample project reproducing the error]https://github.com/Berkeley-CS61B/skeleton-sp21/tree/master/lab2setup

Current Result

• ${project.basedir} is interpreted as a fake absolute path. For example: Users\aoliu\OneDrive\Projects\cs61b-sp21\lab2setup which should be C:\Users\aoliu\OneDrive\Projects\cs61b-sp21\lab2setup in Windows 10.
• ${project.basedir}\src or other path that under the basedir is correctly interpreted. For example: ${project.basedir}\src is interpreted as src, a relative path.
  

从链接的示例项目开始，在 Windows 10 上使用 Java: Configure Classpath 命令重现该问题。比较 ${project.basedir} 和 ${project.basedir}/src 的解析方式；当 basedir 保留其 Windows 驱动器号并生成正确的 classpath 时，即表示完成。