array bindings need to be handled better in the compiler

[Martin Sjölund]

{{{ class ArrayCall

function fn

input Real r;
output Real array[10];

algorithm

array := 1:10.0;
array := cos(r*array);

end fn;
Real x[10] = fn(time);

end ArrayCall;}}}

Either we do common subexpression elimination in the backend or keep the arrays non-expanded. Common subexpression elimination would of course be preferrable as then we could do things like:
{{{class ArrayCall

Real x[10] = fn(time);
Real y[10] = fn(time)*2;
Real z[10] = fn(time)*3;

end ArrayCall;}}}
And only call fn once. We probably need to introduce temporary variables to deal with duplicated function calls.