[foreign] RFR: NoSuchMethodException when symbol not in library

[Henry Jen]

Hi,

Please review the webrev[1] fixes following,

- When a class has declaration of method that doesn’t exist in the library, current implementation will crash the VM by calling into address 0x0. Such scenario should have caused NoSuchMethodException in the Library::lookup. The patch fix this and added a test case.

- A test case where the interface has a method not in declaration, this should not happen with jextract. Just added to make sure nothing bad such as crash VM can happen.

- Fix when return type is Pointer<Void> but the layout is not void. This happens with undefined struct pointer.

- A test case that validate empty struct is handled properly by jextract.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/panama/foreign/missingSymbol/webrev/