restore the mshocks command

git-svn-id: https://www.dynare.org/svn/dynare/trunk@2985 ac1d8469-bf42-47a9-8791-bf33cf982152

DynareFlex.ll

@@ -152,6 +152,7 @@ int sigma_e = 0;
 <INITIAL>endval {BEGIN DYNARE_BLOCK; return token::ENDVAL;}
 <INITIAL>histval {BEGIN DYNARE_BLOCK; return token::HISTVAL;}
 <INITIAL>shocks {BEGIN DYNARE_BLOCK; return token::SHOCKS;}
+<INITIAL>mshocks {BEGIN DYNARE_BLOCK; return token::MSHOCKS;}
 <INITIAL>estimated_params {BEGIN DYNARE_BLOCK; return token::ESTIMATED_PARAMS;}
  /* priors is an alias for estimated_params */
 <INITIAL>priors {BEGIN DYNARE_BLOCK;return token::ESTIMATED_PARAMS;}