tree-vect-patterns.c (vect_recog_dot_prod_pattern): Fix a bug when checking the dot production pattern.

2013-09-17  Cong Hou  <congh@google.com>

    * tree-vect-patterns.c (vect_recog_dot_prod_pattern): Fix a bug
      when checking the dot production pattern. The type of rhs operand
      of multiply is now checked correctly.

    * gcc.dg/vect/vect-reduc-dot-s16c.c: Add a test case with dot product 
      on two arrays with short and int types. This should not be recognized
      as a dot product pattern.

From-SVN: r202663