In C it is possible to create a struct with extra padding such as:

struct Foo {
    int x;
    int : 32;
    int y;
};

Which uses an unnamed bitfield to represent the padding.

It is unclear how the layout for this struct should be constructed. Jextract uses PaddingLayouts, but this might not work on all linker implementations (such as fallback linker).

We should specify and test cases like these in the JDK