Update java.util.date and hack to support date.toInstant and Date.From(instant).

PiperOrigin-RevId: 431763716

Author: mzhang4

jre_emul/android/platform/libcore/luni/src/test/java/libcore/java/util/DateTest.java

@@ -16,6 +16,7 @@
 
 package libcore.java.util;
 
+import java.time.Instant;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.Locale;
@@ -79,4 +80,33 @@ public void test_parse_timezones() {
                 Date.parse("Wed, 06 Jan 2016 11:55:59 GMT+05"));
 
     }
+
+    /**
+     * Checks conversion between long, Date and Instant.
+     */
+    public void test_convertToInstantAndBack() {
+        check_convertToInstantAndBack(0);
+        check_convertToInstantAndBack(-1);
+        check_convertToInstantAndBack( 999999999);
+        check_convertToInstantAndBack(1000000000);
+        check_convertToInstantAndBack(1000000001);
+        check_convertToInstantAndBack(1000000002);
+        check_convertToInstantAndBack(1000000499);
+        check_convertToInstantAndBack(1000000500);
+        check_convertToInstantAndBack(1000000999);
+        check_convertToInstantAndBack(1000001000);
+        check_convertToInstantAndBack(Long.MIN_VALUE + 808); // minimum ofEpochMilli argument
+        check_convertToInstantAndBack(Long.MAX_VALUE);
+        check_convertToInstantAndBack(System.currentTimeMillis());
+        check_convertToInstantAndBack(Date.parse("Wed, 06 Jan 2016 11:55:59 GMT+0500"));
+    }
+    private static void check_convertToInstantAndBack(long millis) {
+        Date date = new Date(millis);
+        Instant instant = date.toInstant();
+        assertEquals(date, Date.from(instant));
+        assertEquals(instant, Instant.ofEpochMilli(millis));
+        assertEquals("Millis should be a millions of nanos", 0, instant.getNano() % 1000000);
+        assertEquals(millis, date.getTime());
+        assertEquals(millis, instant.toEpochMilli());
+    }
 }

jre_emul/android/platform/libcore/ojluni/src/main/java/java/time/Instant.java

@@ -1363,3 +1363,47 @@ static Instant readExternal(DataInput in) throws IOException {
     }
 
 }
+
+/*-HEADER[
+#include "java/util/Date.h"
+
+@class JavaTimeInstant;  // Needed because HEADER comments are grouped with #includes.
+
+@interface JavaUtilDate (JavaUtilTime)
+
+- (JavaTimeInstant *)toInstant;
++ (JavaUtilDate *)fromWithJavaTimeInstant:(JavaTimeInstant *)instant;
+
+@end
+
+FOUNDATION_EXPORT JavaUtilDate *JavaUtilDate_fromWithJavaTimeInstant_(id instant);
+]-*/
+
+/*-[
+
+#include "java/lang/ArithmeticException.h"
+#include "java/lang/IllegalArgumentException.h"
+
+@implementation JavaUtilDate (JavaUtilTime)
+
+- (JavaTimeInstant *)toInstant {
+  return JavaTimeInstant_ofEpochMilliWithLong_([self getTime]);
+}
+
++ (JavaUtilDate *)fromWithJavaTimeInstant:(JavaTimeInstant *)instant {
+  return JavaUtilDate_fromWithJavaTimeInstant_(instant);
+}
+
+@end
+
+JavaUtilDate *JavaUtilDate_fromWithJavaTimeInstant_(JavaTimeInstant *instant) {
+  JavaUtilDate_initialize();
+  @try {
+    return create_JavaUtilDate_initWithLong_([((JavaTimeInstant *) nil_chk(instant)) toEpochMilli]);
+  }
+  @catch (JavaLangArithmeticException *ex) {
+    @throw create_JavaLangIllegalArgumentException_initWithJavaLangThrowable_(ex);
+  }
+}
+
+]-*/