No report for two Classes in the same package with same name

Just as the title says, eclipse will report it.

Environment

• Operating System: Windows 10
• JDK version: 1.8.0_161
• Visual Studio Code version: 1.39.2
• Java extension version: 0.51.0

Steps To Reproduce

// src/test/C1.java
package test;
public class C1 {}
class Same {}

// src/test/C2.java
package test;
public class C2 {}
class Same {}

Current Result

No problem dectected.
Fail to build.

Reproduce the issue using src/test/C1.java and src/test/C2.java, each declaring the same package-private class, and confirm that the extension reports no problem before the build fails. Trace the Java diagnostics entry point that handles duplicate classes, then verify that the duplicate-name problem is reported before or alongside the build failure.