Merge pull request #24248 from JasonFengJ9/valhallaunsafe

Valhalla adds Unsafe.NON_FLAT_LAYOUT

Author: hangshao0

jcl/src/java.base/share/classes/jdk/internal/misc/Unsafe.java

@@ -6710,6 +6710,12 @@ private static char convEndian(boolean isBigEndian, char value) {
 
 	/*[IF INLINE-TYPES]*/
 
+	/**
+	 * The layout value to be checked,
+	 * other values represent some kind of flat layout opaque to Java code.
+	 */
+	public static final int NON_FLAT_LAYOUT = 0;
+
 	/**
 	 * Determines the size of the header for a specified value class
 	 *