Merge pull request #7884 from AlexGhiondea/Port_SecureString

Bring to CoreCLR the SecureString implementation from CoreFx.

diff --cc clr.coreclr.props
Simple merge

diff --cc src/mscorlib/corefx/SR.cs
index e69d6b2,102fb6f..e92cff9
--- 1/src/mscorlib/corefx/SR.cs
--- 2/src/mscorlib/corefx/SR.cs
+++ b/src/mscorlib/corefx/SR.cs
@@@ -494,12 -494,27 +494,32 @@@ namespace Syste
          {
              get { return Environment.GetResourceString("InvalidOperation_NativeOverlappedReused"); }
          }
+         
+         public static string ArgumentOutOfRange_Length
+         {
+             get { return Environment.GetResourceString("ArgumentOutOfRange_Length"); }
+         }
+ 
+         public static string ArgumentOutOfRange_IndexString 
+         {
+             get { return Environment.GetResourceString("ArgumentOutOfRange_IndexString"); }
+         }
+ 
+         public static string ArgumentOutOfRange_Capacity 
+         {
+             get { return Environment.GetResourceString("ArgumentOutOfRange_Capacity"); }
+         }
+ 
+         public static string Arg_CryptographyException 
+         {
+             get { return Environment.GetResourceString("Arg_CryptographyException"); }
+         }
  
 +        public static string ArgumentException_BufferNotFromPool
 +        {
 +            get { return Environment.GetResourceString("ArgumentException_BufferNotFromPool"); }
 +        }
 +
          public static string Format(string formatString, params object[] args)
          {
              return string.Format(CultureInfo.CurrentCulture, formatString, args);

diff --cc src/mscorlib/model.xml
Simple merge

diff --cc src/mscorlib/mscorlib.shared.sources.props
Simple merge