Update ICU to 58.1

source/common/unicode/platform.h

Index: source/common/unicode/platform.h
diff --git a/source/common/unicode/platform.h b/source/common/unicode/platform.h
index 8eed735ac8f92db71dfb45f285463186014e853e..b42bef8323415607d7c71dc144d500c7521a5739 100644
--- a/source/common/unicode/platform.h
+++ b/source/common/unicode/platform.h
@@ -1,7 +1,9 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
 ******************************************************************************
 *
-*   Copyright (C) 1997-2015, International Business Machines
+*   Copyright (C) 1997-2016, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
@@ -428,10 +430,13 @@
 #   define U_HAVE_DEBUG_LOCATION_NEW 0
 #endif
 
-/* Compatibility with non clang compilers */
+/* Compatibility with non clang compilers: http://clang.llvm.org/docs/LanguageExtensions.html */
 #ifndef __has_attribute
 #    define __has_attribute(x) 0
 #endif
+#ifndef __has_cpp_attribute
+#    define __has_cpp_attribute(x) 0
+#endif
 #ifndef __has_builtin
 #    define __has_builtin(x) 0
 #endif
@@ -441,6 +446,9 @@
 #ifndef __has_extension
 #    define __has_extension(x) 0
 #endif
+#ifndef __has_warning
+#    define __has_warning(x) 0
+#endif
 
 /**
  * \def U_MALLOC_ATTR
@@ -514,6 +522,8 @@
  */
 #ifdef U_NOEXCEPT
     /* Use the predefined value. */
+#elif defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS  /* Visual Studio */
+#   define U_NOEXCEPT
 #elif U_CPLUSPLUS_VERSION >= 11 || __has_feature(cxx_noexcept) || __has_extension(cxx_noexcept) \
         || (defined(_MSC_VER) && _MSC_VER >= 1900)  /* Visual Studio 2015 */
 #   define U_NOEXCEPT noexcept
@@ -521,6 +531,24 @@
 #   define U_NOEXCEPT
 #endif
 
+/**
+ * \def U_FALLTHROUGH
+ * Annotate intentional fall-through between switch labels.
+ * http://clang.llvm.org/docs/AttributeReference.html#fallthrough-clang-fallthrough
+ * @internal
+ */
+#ifdef __cplusplus
+#   if __has_cpp_attribute(clang::fallthrough) || \
+            (__has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough"))
+#       define U_FALLTHROUGH [[clang::fallthrough]]
+#   else
+#       define U_FALLTHROUGH
+#   endif
+#else
+#   define U_FALLTHROUGH
+#endif
+
+
 /** @} */
 
 /*===========================================================================*/
@@ -815,6 +843,12 @@
  * This is only used for non-ICU-API functions.
  * When a function is a public ICU API,
  * you must use the U_CAPI and U_EXPORT2 qualifiers.
+ *
+ * Please note, you need to use U_CALLCONV after the *.
+ *
+ * NO : "static const char U_CALLCONV *func( . . . )"
+ * YES: "static const char* U_CALLCONV func( . . . )"
+ *
  * @stable ICU 2.0
  */
 #if U_PLATFORM == U_PF_OS390 && defined(__cplusplus)