Again avoid UBSan "left shift of 65536 by 16 places cannot be represented...

...in type 'int'"; i.e., re-apply 11cc9bdc
"Avoid UBSan 'left shift of 65536 by 16 places cannot be represented..." after
67ef208b "Fixes for migrating SvXMLImport to use
FastParser" removed that fix, for no apparent reason.

Change-Id: I8379d2ae8a39ce8a655688d1168d8de67186472a

include/xmloff/xmltkmap.hxx

@@ -44,7 +44,7 @@ struct SvXMLTokenMapEntry
         nPrefixKey( nPrefix ),
         eLocalName( eName ),
         nToken( nTok ),
-        nFastToken( ( sal_Int32( nPrefixKey + 1 ) ) << 16 | eLocalName )
+        nFastToken( sal_uInt32( nPrefixKey + 1 ) << 16 | eLocalName )
     {
         if ( nFastTok )     // alternative value for duplicate/dummy tokens
             nFastToken = nFastTok;