This fixes the ctrl-arrow support which has been broken by 67be3530.

This helps the compiler to unroll the loop and dodges a crash on OSX. It is
similar to what we do in "loop aL, iX" already.

So the "is_src" argument to shader_dump_arr_entry() is redundant (and wrong).

It's used to determine if the token is a source or destination parameter. A
subsequent patch will split shader_dump_param() in two different functions.

Instead of the usage token.