hg: panama/dev: 8225630: 8225630: Tolerate unsupported type

[henry.jen at oracle.com]

Changeset: cd9cf07652ef
Author:    henryjen
Date:      2019-06-19 10:46 -0700
URL:       http://hg.openjdk.java.net/panama/dev/rev/cd9cf07652ef

8225630: 8225630: Tolerate unsupported type
Reviewed-by: mcimadamore

+ src/java.base/share/classes/java/foreign/memory/UnknownType.java
! src/jdk.jextract/share/classes/com/sun/tools/jextract/TypeDictionary.java
! src/jdk.jextract/share/classes/com/sun/tools/jextract/tree/LayoutUtils.java
! test/jdk/com/sun/tools/jextract/JextractToolProviderTest.java