Properly install gram.h on MSVC builds

This file is now needed by pgAdmin builds, which started
failing since it was missing in the installer builds.

src/tools/msvc/Install.pm

@@ -416,6 +416,8 @@ sub CopyIncludeFiles
         $target . '/include/server/',
         'src/include/', 'pg_config.h', 'pg_config_os.h'
     );
+    CopyFiles('Grammar header', $target . '/include/server/parser/',
+	      'src/backend/parser/', 'gram.h');
     CopySetOfFiles('', 
 				   [ glob( "src\\include\\*.h" ) ], 
 				   $target . '/include/server/');