These patches delete declarations and initializations of variables that are
only assigned to constants but never used otherwise.

The complete semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
type T;
identifier i,i2;
position p;
@@

T i@p;
... 
i = i2

@@
type r.T;
identifier r.i;
constant c;
position p != r.p;
@@

-T i@p;
<... when != i
-i = c;
...>
// </smpl>