Update ICU to 58.1

source/io/ucln_io.cpp

Index: source/io/ucln_io.cpp
diff --git a/source/io/ucln_io.cpp b/source/io/ucln_io.cpp
index 1775d5c509435370e087daaaacb466ec19c36949..21a0baf58db07c45495e30edfc02e7ec255399e5 100644
--- a/source/io/ucln_io.cpp
+++ b/source/io/ucln_io.cpp
@@ -1,3 +1,5 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
 ******************************************************************************
 *                                                                            *
@@ -33,7 +35,7 @@ static const char copyright[] = U_COPYRIGHT_STRING;
 
 static cleanupFunc *gCleanupFunctions[UCLN_IO_COUNT];
 
-static UBool io_cleanup(void)
+static UBool U_CALLCONV io_cleanup(void)
 {
     int32_t libType = UCLN_IO_START;