[foreign] RFR: 8225630: Tolerate unsupported type

[Henry Jen]

Hi,

Another short webrev[1] to make allow jextract go through when encounter unsupported types.

Basically for all unsupported type, we are going to generate a unresolved layout and use the UnknownType as carrier type. Reference UnknownType should cause failure at runtime, while the UnknownType class itself is an indication this function/setter/getter should not be used.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/panama/8225630/0/webrev/