8310591: Missing @since tags in java.lang.foreign

Reviewed-by: mcimadamore

src/java.base/share/classes/java/lang/foreign/SegmentAllocator.java

@@ -69,6 +69,8 @@ import jdk.internal.javac.PreviewFeature;
  * <p>
  * Clients should consider using an {@linkplain Arena arena} instead, which, provides strong thread-safety,
  * lifetime and non-overlapping guarantees.
+ *
+ * @since 19
  */
 @FunctionalInterface
 @PreviewFeature(feature=PreviewFeature.Feature.FOREIGN)

src/java.base/share/classes/java/lang/foreign/SymbolLookup.java

@@ -118,6 +118,8 @@ import java.util.function.BiFunction;
  * SymbolLookup stdlib = nativeLinker.defaultLookup();
  * MemorySegment malloc = stdlib.find("malloc").orElseThrow();
  *}
+ *
+ * @since 19
  */
 @PreviewFeature(feature=PreviewFeature.Feature.FOREIGN)
 @FunctionalInterface

src/java.base/share/classes/java/lang/foreign/package-info.java

@@ -147,6 +147,10 @@
  * access to restricted methods is enabled for all modules, but access to restricted methods will result in runtime warnings.
  *
  * @spec jni/index.html Java Native Interface Specification
+ *
+ * @since 19
  */
+@PreviewFeature(feature=PreviewFeature.Feature.FOREIGN)
 package java.lang.foreign;
 
+import jdk.internal.javac.PreviewFeature;