The source launcher in modular mode fails to execute an inherited main method, if it is inherited from a package other than the package of the main class.

```
/// A.java
package a;
import b.B;
public class A extends B {}

/// src/b/B.java
package b;
public class B {
  public void main() { IO.println("B"); }
}

/// module-info.java
module anything {}
```

```
$ java a/A.java
Exception in thread "main" java.lang.reflect.InaccessibleObjectException: Unable to make public void b.B.main() accessible: module random does not "exports b" to module jdk.compiler
        at java.base/java.lang.reflect.AccessibleObject.throwInaccessibleObjectException(AccessibleObject.java:343)
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:319)
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:267)
        at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:182)
        at java.base/java.lang.reflect.Method.setAccessible(Method.java:176)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.execute(SourceLauncher.java:257)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.run(SourceLauncher.java:138)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.main(SourceLauncher.java:76)
```

This case can be fixed by modifying the logic in `com.sun.tools.javac.launcher.MemoryContext::newClassLoaderFor` to not only `addOpens` for the package of the main class, but also for the package wherein the main method resides.

Note: this case works fine if we remove the `module-info.java` as then no module layer is created.