Add back ErrorLogPath to prevent a breaking change

src/Compilers/Core/Portable/CommandLine/CommandLineArguments.cs

@@ -129,6 +129,12 @@ public abstract class CommandLineArguments
         public ErrorLogOptions? ErrorLogOptions { get; internal set; }
 #nullable restore
 
+        /// <summary>
+        /// Options controlling the generation of a SARIF log file containing compilation or
+        /// analysis diagnostics, or null if no log file is desired.
+        /// </summary>
+        public string ErrorLogPath => ErrorLogOptions?.Path;
+
         /// <summary>
         /// An absolute path of the app.config file or null if not specified.
         /// </summary>