Update ICU to 58.1

source/common/unifiedcache.h

Index: source/common/unifiedcache.h
diff --git a/source/common/unifiedcache.h b/source/common/unifiedcache.h
index 35dabbb535c976085376601365e16f6a9af09f0b..72b8a791313a663423799481c89dbeb304216699 100644
--- a/source/common/unifiedcache.h
+++ b/source/common/unifiedcache.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) 2015, International Business Machines Corporation and
@@ -140,7 +142,7 @@ class LocaleCacheKey : public CacheKey<T> {
            : CacheKey<T>(other), fLoc(other.fLoc) { }
    virtual ~LocaleCacheKey() { }
    virtual int32_t hashCode() const {
-       return 37 *CacheKey<T>::hashCode() + fLoc.hashCode();
+       return (int32_t)(37u * (uint32_t)CacheKey<T>::hashCode() + (uint32_t)fLoc.hashCode());
    }
    virtual UBool operator == (const CacheKeyBase &other) const {
        // reflexive