Use CharUnicodeInfo from corert to fix webgl failure

Author: Michael DeRoy

mcs/class/corlib/System/Debug.cs

@@ -0,0 +1,13 @@
+//Stubs for Assert used by CharUnicodeInfo pulled in from corert
+namespace System.Globalization
+{
+	public static partial class CharUnicodeInfo
+	{
+		internal static class Debug
+		{
+			internal static void Assert(bool condition, string message)
+			{
+			}
+		}
+	}
+}

mcs/class/corlib/corlib.dll.sources

@@ -1111,7 +1111,9 @@ ReferenceSources/AppContextDefaultValues.cs
 ../referencesource/mscorlib/system/globalization/CalendricalCalculationsHelper.cs
 ../referencesource/mscorlib/system/globalization/calendardata.cs
 ../referencesource/mscorlib/system/globalization/calendarweekrule.cs
-../referencesource/mscorlib/system/globalization/charunicodeinfo.cs
+System/Debug.cs
+../../../external/corert/src/System.Private.CoreLib/src/System/Globalization/CharUnicodeInfo.cs
+../../../external/corert/src/System.Private.CoreLib/src/System/Globalization/CharUnicodeInfoData.cs
 ../referencesource/mscorlib/system/globalization/chineselunisolarcalendar.cs
 ../referencesource/mscorlib/system/globalization/compareinfo.cs
 ../referencesource/mscorlib/system/globalization/culturenotfoundexception.cs