Use optional parameter in SniErrorDetails constructor

Author: edwardneal

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs

@@ -62,7 +62,7 @@ internal readonly struct SniErrorDetails
             public readonly string Function;
             public readonly Exception Exception;
 
-            internal SniErrorDetails(string errorMessage, uint nativeError, uint sniErrorNumber, int provider, uint lineNumber, string function, Exception exception)
+            internal SniErrorDetails(string errorMessage, uint nativeError, uint sniErrorNumber, int provider, uint lineNumber, string function, Exception exception = null)
             {
                 ErrorMessage = errorMessage;
                 NativeError = nativeError;
@@ -72,16 +72,6 @@ internal SniErrorDetails(string errorMessage, uint nativeError, uint sniErrorNum
                 Function = function;
                 Exception = exception;
             }
-
-            internal SniErrorDetails(string errorMessage, uint nativeError, uint sniErrorNumber, int provider, uint lineNumber, string function)
-            {
-                ErrorMessage = errorMessage;
-                NativeError = nativeError;
-                SniErrorNumber = sniErrorNumber;
-                Provider = provider;
-                LineNumber = lineNumber;
-                Function = function;
-            }
         }
 
         private sealed class TimeoutState