Fix compat with newer MSVC headers

allow using older versions of clang than 19 until mono#1942

Author: mitchcapper

src/Parser/ParserOptions.cs

@@ -156,10 +156,11 @@ public void SetupMSVC(VisualStudioVersion vsVersion)
 
             var clVersion = MSVCToolchain.GetCLVersion(vsVersion);
             ToolSetToUse = clVersion.Major * 10000000 + clVersion.Minor * 100000;
-            
+
             AddArguments("-fms-extensions");
             AddArguments("-fms-compatibility");
-            AddArguments("-fdelayed-template-parsing");
+			AddArguments("-fdelayed-template-parsing");
+			AddArguments("-D_ALLOW_COMPILER_AND_STL_VERSION_MISMATCH");
         }
 
         /// <summary>