Update ICU to 58.1

source/i18n/unicode/udatpg.h

Index: source/i18n/unicode/udatpg.h
diff --git a/source/i18n/unicode/udatpg.h b/source/i18n/unicode/udatpg.h
index aa4ca7a923cf19c9319c3b3cc1f8fae666468a30..47d3afb1d0cbf208634c71bcb788ae76ea12ca80 100644
--- a/source/i18n/unicode/udatpg.h
+++ b/source/i18n/unicode/udatpg.h
@@ -1,3 +1,5 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
 *******************************************************************************
 *
@@ -83,7 +85,13 @@ typedef enum UDateTimePatternField {
     UDATPG_FRACTIONAL_SECOND_FIELD,
     /** @stable ICU 3.8 */
     UDATPG_ZONE_FIELD,
-    /** @stable ICU 3.8 */
+
+    // Do not conditionalize the following with #ifndef U_HIDE_DEPRECATED_API,
+    // it is needed for layout of DateTimePatternGenerator object.
+    /**
+     * One more than the highest normal UDateTimePatternField value.
+     * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
+     */
     UDATPG_FIELD_COUNT
 } UDateTimePatternField;
 
@@ -120,8 +128,13 @@ typedef enum UDateTimePatternConflict {
     UDATPG_BASE_CONFLICT,
     /** @stable ICU 3.8 */
     UDATPG_CONFLICT,
-    /** @stable ICU 3.8 */
+#ifndef U_HIDE_DEPRECATED_API
+    /**
+     * One more than the highest normal UDateTimePatternConflict value.
+     * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
+     */
     UDATPG_CONFLICT_COUNT
+#endif  // U_HIDE_DEPRECATED_API
 } UDateTimePatternConflict;
 
 /**