Update ICU to 58.1

source/i18n/islamcal.h

Index: source/i18n/islamcal.h
diff --git a/source/i18n/islamcal.h b/source/i18n/islamcal.h
index 75f9656de94ce2ccdb50e79e834b7e1f4db936e8..7f6faed8867a9373050b8dd697ba442b2e55ee81 100644
--- a/source/i18n/islamcal.h
+++ b/source/i18n/islamcal.h
@@ -1,3 +1,5 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
  ********************************************************************************
  * Copyright (C) 2003-2013, International Business Machines Corporation
@@ -417,7 +419,7 @@ class U_I18N_API IslamicCalendar : public Calendar {
    * are considered to fall within so that its start date is 80 years
    * before the current time.
    */
-  static void  initializeSystemDefaultCentury(void);
+  static void U_CALLCONV initializeSystemDefaultCentury(void);
 };
 
 U_NAMESPACE_END