This pass reduces the dimension of an array. Each transformation iteration
reduces one dimension in the following way:
  int a[2][3][4];
  void foo(void) {... a[1][2][3] ... }
===>
  int a[2][3 * 4];
  void foo(void) {... a[1][3 * 2 + 3] ... }
The binary operations will be computed to constant during the
transformation if possible. Array fields are not handled right now.
Also, this pass only works with ConstantArrayType and IncompleteArrayType.